LOW-VISIBILITY DIVING HIGH-PRESSURE HOSES IMPROVE YOUR BREATHING WHEN SHOULD THE RESCUE BEGIN TREATING THE BENDS June/July/August 2022 YOURDIVESAFETYORGANISATION
FEATURES
WEATHER,
Diving inherently carries an elevated level of risk because humans cannot survive underwater without specialised equipment An effective rescue is vital for a favourable outcome when things go wrong. Most rescue diver courses teach students basic techniques to apply after something goes wrong, but better courses also provide strategies to prevent incidents from occurring in the first place
SILTY SEDIMENT, time of day, or water movement are just a few natural factors among the range of possible causes that can influence the visibility at your dive site Low visibility diving can be quite enjoyable, but it depends on the circumstances and your comfort level DAN IS YOUR DIVE SAFETY ORGANISATION On the Cover Photo donated to DAN by Dr Cleeve Robertson Anemone shot on the famous Aliwal Shoal, Landers Reef with Nikon 810 in a Nauticam housing using a Nikon 60mm Lens at F16, ISO100 and 1/100 sec. by Dr Cleeve Robertson Contributors Page 25 Low Visibility Diving Frauke Tillmans, PhD Grant Dong Jim Gunderson Christine Tamburri Keli Cuppett Paul Lensen Francois Burman, PR ENG , M SC Jacques Davie DAN Medical Team Contact Us Contact Us Please contact us at mail@dansa.org or phone +27 11 266 4900. In a diving emergency call the DAN Hotline on +27 82 810 6010 ALERT DIVER LITE
Team Dr Frans Cronje Morné Christou ALERT DIVER LITE | 1
Page 47 When Should the Rescue Begin?
CONTENTS 3 Perspectives 5 Cape Town Dive Festival Industry News 9 Why Women Love Diving Dive Slate 19 Scuba Diving & the Lessons for a Start-Up Dive Slate 21 Women in Diving Danel Wentzel Dive Slate 30 From the Medical Line Research, Education & Medicine 53 Catalogue DAN Products JUNE/JULY/AUGUST 2022 51 RISK MITIGATION: High Pressure Hoses 41 RESEARCH PROFILE: What Does It Mean? 15 DIVE SLATE: Treating the Bends Part 1 35 Improve Your Breathing Practising rhythmic breathing without breath holding can benefit divers. ALERT DIVER LITE | 2
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PERSPE CTIVES
There is virtually no aspect of diving that does not benefit from thorough preparation Preparation for scuba diving begins long before arrival at the dive site, and involves a blend of knowledge and skill As a broad overview for preparation, let us consider your personal, safety goody bag which identifies the parameters within which you can dive with relative safety. Each of us has our own personal safety interlock which is defined by experience and qualifications as a diver The more experience, practice (especially recent practice) and knowledge you have of essential diving and safety skills, the larger your personal, safety goody bag becomes The reverse is also true: If you have very limited experience, have not practised your skills for some time and have not taken advantage of continuing education opportunities, then your personal safety goody bag limits the kind of diving you should do.
To help you be better prepared, DAN developed diving first aid courses and online safety podcasts to provide divers with the knowledge and tools necessary, not only to manage diving emergencies, but also understand how to recognise and mitigate risks. Our expert medical staff writes articles for the Alert Diver as well as other publications Essential information for making decisions regarding your (and your buddy’s) safety can be found on the DAN Blog at www dansa org/blog Take advantage of DAN’s hotline service (+27 828 10 60 10) and speak directly to staff who can answer questions and provide information on diving related issues All these resources give you valuable knowledge and the tools to help you make the correct choices before diving.
The saying: “Dive your experience, not your certification card”, is a great one to remember Your C card grants you the opportunity to dive Your experience helps you to safely take advantage of the opportunity It is crucial to have all the information needed to make good decisions about the dive you are planning. Besides the basic skills it takes to enjoy the dive, you should be healthy, fit and confident that your skills and abilities match the dive’s potential demands Being well prepared also includes making sure you have the right gear for the dive. It should be inspected annually and maintained by a qualified technician. It is critical that your equipment, like you, meets the potential demands of the dive Do not underestimate the value of comprehensive pre dive planning and a thorough checklist Establishing a pre dive plan and using a checklist will help you and your buddy make sure that everything is done properly before entering the water, thus reducing the likelihood that an otherwise enjoyable dive will turn into a tragedy for you and others.
So review your training from time to time, practise little used skills and seek local knowledge Learn from DAN, learn from your (and others’) mistakes and do not miss opportunities that will allow you to better prepare yourself for safer diving.
Morne Christou Chief Executive Officer
On shore, the stalls from DAN Southern Africa, Dive Action/Nauticam Housings, Coral Wetsuits, Alpha Dive Centre, NAUI Freedivers and REEF Wetsuits, to name a few, kept the crowds busy while others were out diving
Dive Slate
NEWS
This year the freedivers had boats exclusively available to enjoy the reefs far from the shore The participating divers returned with beaming smiles and reported flat sea conditions and incredibly blue water, with 15m visibility underwater a rare site for Cape Town The great weather and sea conditions made for easy, relaxed diving. One of the most exciting sightings was four Mola Mola (ocean sunfish) cruising past the divers enjoying a dive at Outer Photographer's reef
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INDUSTRY
This year the bi annual Cape Town Dive Festival took place in May, and we saw divers from as far as Sodwana Bay and Johannesburg visit the festival at the False Bay Yacht Club The festival started in 2012 and is held every two years. Due to the Covid pandemic, the dive festival did not go ahead in 2020 OMSAC and the False Bay Underwater Club organised this year's festival More than 120 scuba divers and freedivers registered for the dive spots available on the chartered boats The chartered boats from Blue Flash, Dive Team, Dive Action, Oceans Africa, Pisces Divers, and Underwater Explorers completed 24 launches to various dive sites around False Bay. They enjoyed the best that Cape Town has to offer divers! A combination of reef and wreck dives was available for divers of all levels to enjoy
By The DAN Team Cape Town Dive Festival 2022
The DAN Corner was manned by Dr. Frans & Sr. Lucie Cronje, who set up their video
The Durban Undersea Club, with the generous support of committed sponsors and dedicated volunteers, is proud to host the 10th DUC Shootout. The DUC Shootout seeks, through a visual medium, to: The Durban Undersea Club Shootout (“the DUC Shootout”) aims to be one of the most prestigious competitions of its 2022 DUC SHOOTOUT
otoscope to show divers what happened inside their ears when they equalised or suffered barotrauma. Many divers frequented the DAN Coner to ask Dr Cronje general dive medical questions and learn more about the different DAN services. Fortunately, there were no incidents that required emergency action or treatment. After the day's diving, festival goers gathered around to enjoy hot beverages, soups and boerie rolls while waiting for the raffle draw. The organisers were grateful for the generous sponsorships from the different dive industry partners, which included: Reef Wetsuits, DAN Southern Africa, Kief Divers, Gozo Azul & Planet Scuba in Mozambique, RAID and Dive Inn, Naui Freediving Africa, DMD Fins, Alpha Dive Centre, Scubapro, Cape Scuba Club, Salteez, Cape Nudibranchs, Orca Industries, Oceanic, Flatdog Bodyguard Sunscreen, DiveTek, Cape Gear, Underwater Explorers, Manex Power Marine, Coral Wetsuits, Animal Ocean, Dive Action, Brightweights and SA Paramedics. Thank you to the False Bay Yacht Club for hosting the event The divers certainly enjoyed the well organised event, and they look forward to the 2024 Cape Town Dive Festival. promote inland and coastal waters of Southern Africa as diving destinations, promote an understanding and appreciation of the diversity and beauty of the underwater world and the need to preserve it, celebrate the already high standard of underwater photography in the wider diving community and encourage the growth of underwater photography, promote the discovery, understanding, and responsible enjoyment of the underwater world, and encourage innovation and creativity whilst maintaining excellence in underwater photography
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kind, attracting entries from professionals and amateurs worldwide The Durban Undersea Club invites entries to the DUC Shootout from amateur and professional photographers The images entered in the competition may be featured in various media and/or exhibitions to increase awareness of the beauty of the Southern African underwater world and the promotion of South Africa as a diving destination Shooting must take place in the natural inland and coastal waters of Southern Africa. Rivers, lakes, lagoons, springs, rock pools and quarries are defined as “natural inland waters” Swimming pools and aquariums are not defined as natural inland waters Southern Africa is defined as Mozambique, Botswana, Namibia, Zimbabwe and Lesotho ADL
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Cecilia made significant contributions as a leader in Diving and Hyperbaric Medicine She was also an occupational diving medical specialist and will be missed by our commercial diving members In the process of living her life, she improved the lives of everyone she came in contact with Her grace, humour and brightness of spirit was an inspiration to all who knew her She was an extraordinary person in every way To her family, we can only express our heartfelt condolences, and thank them for sharing with us such a vibrant and enthusiastic diving buddy 1978 to 2022 Roberts
DAN was devastated to learn of the passing of Dr Cecilia Roberts, one of our dedicated, long standing, volunteer Diving Medical Officers Cecilia was always willing to put up her hand when we needed an on site presenter for our DAN Divers Days, regardless of the location She unselfishly gave her time and expertise, never mind the hour of the day or night Her wonderful sense of humour, especially while we were on the road together, will be so sorely missed
O B I T U A R Y Cecilia
D I V E S L A T E
By Kate Jonker
As a "Scuba Girl" myself, I am often asked why I love scuba diving There are so many reasons, and these vary from person to person When I decided to learn to scuba dive, my friends thought I was crazy. “Women can’t scuba dive!” they said… “What about all that heavy stuff?” … “Only guys dive and they’ll just look at you as a burden” “It’s just not something women do!” Those comments were made by my non scuba diving friends (male and female). After seeing how much fun I was having, however, they have dived right in and are now fellow scuba divers. And loving it, too! Scuba diving provides a wonderful bonding experience for families and it is something mothers and daughters can do together.
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#WHYWEDOIT
WHY WOMEN LOVE DIVING
When I started diving, I was the only woman on my Open Water Scuba Diver Course. I was only one of two ladies on my Advanced Course At that time there were less women in our diving group than men But that did not bother us we all absolutely loved Scuba Diving! So, what kind of women love scuba diving? The ladies that belonged to my dive club came from all age groups and levels of fitness We had a 16 year old learning to dive with her 40 year old mother We had a grandmother of fifty six as well as women who participated in triathlons In addition, there were some ladies whose only exercise was the walk from the car into the Wimpy. We all kept up with the boys, carried our own weights and cylinders. Not to mention that we were often able to beat the boys at their joke telling! Why do women learn to scuba dive? That was 22 years ago. Nowadays the men taking scuba classes are being outnumbered by the ladies. Quite a few of our students learn to dive so that they can join their partners on diving trips. They do not want to be left on the shore any longer! In general, we do not want to listen to how great the dive was we want to experience it for ourselves Other reasons for the increase in ladies wanting to learn to dive is that they want to try something different. Or they “just always wanted to do it but never found the right person to teach them.” Whatever the reason, after their first dives most are absolutely hooked Already in love with scuba diving, they are eager for their next dive!
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Scuba diving is easier than you think! Although scuba diving does require a certain level of strength and fitness, it is not as strenuous as one expects The bonus is, the more you dive, the fitter you become Even if you can do it all yourself, there is always a gentleman somewhere wanting to help. Swallow your pride ladies, let them carry your weight belt or cylinder, just smile, and say, “thank you!” I am still teased for growling back "I can do it myself" all those years ago It earned me the nickname "Kwaai Kate" Nowadays, I smile and am grateful Not always glamorous I won’t deny that there are a couple of minor drawbacks of being a female diver For example those neatly manicured long nails they will not stay like this for long Nails break easily, usually when pulling on wetsuits, picking up weights and climbing over rocks The solution keep your nails short Long hair can also be a problem. If yours is like mine, you will always have a bird’s nest / dreadlock hairdo after diving. However, plaiting your hair or simply saturating your hair with fresh water before a dive can help Shore diving comes with its own challenges How often will you find a bathroom on a remote beach? Guys have it easy. We must find a bush or make a plan. It is all about being creative and we are good at that, right? But then, there may be some gentlemen reading this, so we will chat about this on our next dive, OK? 2
DIVE SLATE
#WHYWEDOIT CONTINUED
Kate Jonker a writer and underwater photographer based in Gordon’s Bay, just outside Cape Town She is a regular contributor to numerous underwater photography and diving magazines and her images have been featured in both local and international publications A regular judge in international underwater photography competitions, she teaches underwater photography and is a qualified dive boat skipper and dive guide for Indigo Scuba Diving Centre, which she and her husband own and run in Gordons Bay Kate’s passion lies with sharing her love of the ocean and her underwater experiences with others through photography and storytelling
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“Photography is a fantastic medium with which to create an awareness of the beauty and plight of our oceans Images can stir many emotions and we, as underwater photographers, have the opportunity to tell visual stories about our underwater world to encourage its protection and preservation” Kate Jonker Links
Amazing benefits Diving really is an amazing sport for women. For instance, the places it can take you to, the great people you meet and the wonderful things you see There is nothing like it! Coupled with the feeling of total peace during a dive makes this an unbeatable sport You will feel so relaxed after diving, too. So, if you have not taken the plunge already sign up for an Open Water Diver Course right now! You will soon realise why women just like you love scuba diving! ADL Website wwwkatejonkercom Instagram https://wwwinstagramcom/katejonkerphotograph y/ Facebook https://wwwfacebookcom/KateJonkerPhotograph y YouTube https://wwwyoutubecom/channel/UCUOVIfi0qD GMRfiRUzeZ TQ Indigo Scuba Links Website wwwindigoscubacom Instagram https://wwwinstagramcom/indigoscuba/ Facebook https://wwwfacebookcom/indigoscuba/ YouTube https://wwwyoutubecom/user/IndigoScuba
KATE JONKER Biography
Shore diving comes with its own challenges How often will you find a bathroom on a remote beach? Guys have it easy We must find a bush or make a plan. It is all about being creative and we are good at that, right? But then, there may be some gentlemen reading this, so we will chat about this on our next dive, OK?
Not always glamorous I won’t deny that there are a couple of minor drawbacks of being a female diver For example those neatly manicured long nails they will not stay like this for long Nails break easily, usually when pulling on wetsuits, picking up weights and climbing over rocks. The solution keep your nails short. Long hair can also be a problem. If yours is like mine, you will always have a bird’s nest / dreadlock hairdo after diving However, plaiting your hair or simply saturating your hair with fresh water before a dive can help.
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By Dennis Guichard
THE BENDS THE CHAMBER ATTENDANT P A R T 1 T R E A T I N G
The human psyche is an endlessly fascinating psychological topic to study How we all so commonly develop our own deep rooted 'right' and 'wrong' belief systems and adhere to those unwaveringly from the depths of our ideological bunkers But how so many of us choose to live at the cusp of life dancing with misadventure and breaking the rules with scant regard indeed just because they're seemingly begging us to.
There are, of course, lines of argument that propose that rules can only be defined in the first place by the rule breakers who endlessly test their validity in a phenomenon known as the ‘normalisation of deviance’, where any particular 'rule' exists Still, we choose to test that rule and, by chance, get away with flouting it, thus believing the rule had no basis, thereby establishing a 'new rule' of our own for what we think is safe and acceptable practice when all that happened is we had been getting lucky with bending the original rule and getting away it Flouting the risk of decompression sickness certainly falls into this arena
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I'm not anti risk, but the risk can always be calculated and managed with a clear, competent mind Competency, however, requires training and gaining experience learning from others who have been on that path of adventure and learning themselves previously DAN Instructors offer courses on various subject matters relating to diving first aid, decompression theory, and risk management. Many amazing DAN courses are available online or directly through your local dive centre
Diving safety has grown in leaps and bounds through the many decades I've been diving and Instructing, thanks in momentous proportions to the incredible extent of research and education provided by DAN worldwide Dive tables were revised to improve safety Safety stops have become commonplace Divers widely now understand the critical nature of controlling their ascent rates. Nowadays, it is estimated that some 95% of divers use dive computers to manage their dives better Despite all of these safety advancements, however, data from survey questionnaires returned by 740 recreational divers, 365 professional divers, and 112 saturation divers in Norway found that 19% of the recreational divers, 50% of professional divers, and 63% of saturation divers had experienced symptoms of decompression sickness that they never reported nor sought treatment for them There's not a weekend that I'm out on the dive boats locally that I don't see recreational divers pushing their bottom times going into compulsory decompression with the intent to work that time off on their safety stop, divers doing explosive ascents with minimal safety stop times, or the conversation arising around the dive camp about which favoured dive computer to buy that gives the most bottom time.
Mild cases of Decompression Sickness often don't even need hyperbaric recompression They are often resolved by simply administering normobaric (sea level atmospheric pressure) 100% O2 from a non rebreather face mask and the adequate ingestion of fluids either orally or via an intravascular drip For a case to be considered ‘mild’, however, there must be a neurological examination performed by a hyperbaric physician to exclude any risk of neurological complications Decompression sickness certainly still occurs amongst divers, and diver denial remains one of the most significant risks for residual injury that might otherwise be avoidable. There is a common misplaced belief that as long as we dive within the maximum no deco times permitted by our dive computer, that is sufficient to keep us bend free Yet DAN analysis statistics show us that 86% of divers who bend are within the maximum allowable dive time limits provided by their dive computers Decompression sickness does not generally form immediately during or even directly after surfacing from a dive, even when tissue supersaturation levels are very high. There is typically a delay before signs and symptoms present themselves Reportedly 50% of cases will show within 30 minutes, 85% within an hour, 95% within 3 hours, and only 1% after more than 6 hours have passed.
One of the most topical conversations in scuba diving is currently around the subject of ‘Human Factors' in diving accidents and dive safety. It's unquestionably each diving mannerism that defines how our weekends might play out and whether we get to spend time at our favourite local hyperbaric facility being nursed by a Chamber Attendant. Our wellbeing is undoubtedly in our own hands, defined by the mannerism we choose to manage our level of risk
On the other hand, lower spinal cord symptoms, such as paralysis or bladder dysfunction, seem to arise more often after deeper bounce dives. However, while these observations can be attributed to the saturation desaturation behaviour of the affected tissues, they cannot be relied upon blindly. Any symptom within hours after surfacing from a dive with a certain degree of inert gas saturation should be considered decompression related unless another, more prominent cause can be pinpointed with a fair dose of humility It is suggested that once decompression sickness is present, it rapidly triggers biochemical and biophysical reactions and becomes a systemic disease rather than just 'bubble trouble' that is treatable with hyperbaric therapy; hence you must seek professional guidance by phoning the DAN hotline for early intervention if you suspect that you might have some form of decompression sickness
The time of onset of symptoms depends to some degree on the type of dive Deep dives, especially those that require decompression or are close to the no deco time limits (because don't we all typically dive our computers to the limit) or in which decompression has been omitted, are more likely to present early. Whilst joint pain symptoms in limbs (Type 1 DCS) are more frequently observed after long dives to relatively shallow depths In general, the earlier the signs, the more potentially serious the form of decompression sickness.
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Cardiopulmonary decompression sickness (more commonly referred to as the 'Chokes') is rare but frequently fatal. Also, it appears more suddenly upon often surfacing due to severe provocative dive profiles where compulsory decompression stops might have been missed The onset of Arterial Gas Embolism is also more immediate and may indeed even occur whilst the diver is still in the water or immediately upon surfacing
When you have been assessed via the DAN call centre, protocols will be activated (particularly after hours or over a weekend) to get the relevant friendly chamber staff into the facility in preparedness for your arrival
The chamber attendant is undoubtedly the person you will get to know the best, as the shortest treatment, even just for mild cases of pain only decompression sickness, are anything between 2 hours 15 minutes to 4 hours 45 minutes long
Generally speaking, about 30% of all divers who get decompression sickness suffer some residual outcome even after complete and timely hyperbaric treatment inner ear DCS appears to cause permanent damage, and neurological DCS often does not heal completely.
The diving physician is the guru of all things with the knowledge set of an android The chamber operator is commonly paramedical qualified with the technical skillset of an A380 Airbus pilot, but the hyperbaric qualified chamber attendant is most often certainly the cutest of the lot The chamber attendant will most often be qualified in the fundamentals of hyperbaric medicine as a Certified Hyperbaric Technologist and maybe a professional nurse or paramedic or might be a commercial diver/saturation medic. They are often also directly involved in SCUBA diving themselves as Instructors or experienced divers so intimately understand the physics and physiology of decompression theory.
The most extended treatment table for severe decompression sickness, used for uncontrolled ascents when more than 60 minutes of compulsory decompression have been omitted (if you even survive an ascent and tissue loading of that nature), can be up to 65 hours 29 minutes long
It’s the chamber attendant who is going to hold your hand for the hours you are in the 'pot'; who is going to keep you in good spirits and help administer any medication you might need during the treatment; who is going to tell you bad jokes, offer to play a game of cards, and who is going to look after your wellbeing from start to finish directly There are easier ways to meet one if you're hoping to. Still, if push comes to shove, hyperbaric chamber attendants certainly are Superstars giving freely of themselves to help ensure your ultimate wellbeing ADL
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Dennis Guichard is a multi agency qualified Scuba Instructor Trainer and a DAN ‘Master Dive Pro’ member He is qualified as an offshore saturation medic and a Hyperbaric Technologist freelancing as a chamber operator and attendant at the Netcare St Augustine’s Hospital Hyperbaric Medicine and Wound Care Unit, Durban, South Africa
Of course, all of the/any hyperbaric facility staff are highly qualified and experienced in subsea and hyperbaric medicine related matters in various forms
Once you’ve called the DAN Hotline (phone: +27 82 810 6010 in South Africa) and received a preliminary assessment from any of the most wonderful call centre staff, you may be referred to your nearest DAN partner hyperbaric chamber facility which in Durban would be the St Augustine’s Hospital Hyperbaric and Wound Care Unit
Fortunately, incidents of decompression sickness are rare they form a minuscule proportion of the disorders we get to treat at any hyperbaric medical centre If you're going to get decompression sickness, then more often than not, the chances are your bend might develop into a neurological one. That is reason enough always to call the DAN helpline when in any doubt.
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SCUBA DIVING & THE LESSONS FOR A START-UP BY PAUL LENSEN
Stop Breathe Think and then Act I stopped panicking (sort of) and focussed on finning (kicking) to keep my head above the surface At this point, I was still not sure what had caused me to sink. I placed my regulator back into my mouth and breathed Towards the end of 2021, I decided to leave my job and start my own business It was a daunting and difficult decision, but I thought about it as the pandemic continued to show me what really mattered: A work life balance and following a passion for filmmaking that started when I was at school.
At the same time, I decided to start Scuba Diving. I lived in Cape Town my whole life, and the beautiful waters surrounded the city I had only seen from above, not below. I loved the idea of a fantastic world beneath the waves, and the boy inside me wandered about buried treasures and shipwrecks So I took the plunge, literally and figurately diving into the unknown I have learned so far: there are many similarities between scuba diving and entrepreneurship who would have thought A few weeks ago, I was out on a boat dive I was excited to be out in the open ocean, ready to descend to one of the more accessible shipwrecks off the Simons Town coast the PMB. The sun was hot, and the conditions were not ideal heavy wave action on the surface, still safe for a controlled descent to the bottom After our safety briefing from the DM (Dive Master) and safety check with our buddy: air in the BCD (Buoyancy Compensator Device), regulator check, weights, masks, we were good to go. “Rollback on 3” and off we went. And then the trouble started As I bobbed up and righted myself, I immediately started sinking FAST I finned and kicked to stay afloat, my head just above the surface. I began to panic, but fortunately, this is when the training kicked in.
these two actions allowed me to move into a solution focused mode quickly, and I could think: Do I need to drop my weights? No, if I did descend, I could keep finning, as I was now breathing through my regulator to deal with the situation more easily ‘Signal to my buddy’ Of course, this is buddy sport Turning to my right, there he was, swimming towards me I acted, signalled, and indicated what I thought the issue was becoming clearer as I breathed and focussed I pointed to a pull tag above my right BCD strap I figured it had got “trapped” and was dumping air while inflating it. He quickly unhooked it, and I was able to gain positive buoyancy He signalled to me that familiar (and reassuring) diver “OK” sign, and we were good to go to continue the dive. The parallel between this experience and being an entrepreneur is quite similar. Being confronted with a problem or a ‘crisis ‘ we panic Take knee jerk decisions and react in ways that seem right in the short term (dump the weights end the dive) instead of stopping, breathing, and then taking a solution focussed approach (kick, fin up OK, I can do this, while I breathe and think of the next step) And then to Act Like turning to your buddy, signalling that you need help As In business, you do not need to do this alone signal to a colleague, mentor, or even your share holders, that you need assistance but here is the kicker: You need to stop and in a calm (not easy), rational, and even imperfect way ask for what you need, help “I am sinking it could be this can you assist” The action is humbling, it can be exposing, it makes you vulnerable but the reward: In my case, I got to continue and enjoy the dive! ADL
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W O M E N I N D I V I N G ALERT DIVER LITE | 21 D I V E S L A T E
It is said that the South African coast is one of the most biologically diverse and complex marine environments on earth. The coastline stretches for 2 850 kilometres from the Namibian border in the west to the Mozambique border in the east
Danel Wentzel
By Nicolene Olckers
Photo by Danel Wentzel
On the west coast, the nutrient rich cool waters of the Atlantic Ocean are home to some of the world's largest seal colonies, endemic penguins and masses of seabirds You will also find the giant Atlantic Kelp forests that sway on the tides Without a doubt, the Benguela current makes for vibrant and diverse sea life On the east coast, the warmer, tropical waters of the Indian Ocean are home to world renowned, brightly coloured coral reefs and its lush diversity of coral reef fishes and the powerful Agulhas current
It is not surprising that marine biologists worldwide visit our country to do research and find unique and incredible subjects to study for their PhD or master's degrees But we also have some of the finest researchers and students that are South African born and have grown up with the salty seas in their veins
One of these salty wanderers is Danel Wentzel. This 23 year old PADI Scuba Instructor and Marine biologist resides in Muizenberg, Cape Town Danel recently completed her Honours degree in Marine Biology at the University of Cape Town She is passionate about exploring and protecting our oceans and sharing knowledge with others. Besides diving, Danel runs the social media for the Save Our Seas Foundation Shark Education
After that, I started working for the I Am Water Foundation It also worked with kids, teaching them about the ocean's creatures and plastic pollution and introducing them to snorkelling Working with kids is something I am super passionate about. Building their confidence in the ocean and having them experience the
Being a Marine Biologist what is your field of study? Are you specialising in any specific marine species or environment? I completed my Honours degree in marine biology at the University of Cape Town in December 2020 My thesis looked at the dynamics and seasonality of Anaulus Australis, which is a surf zone diatom that forms big brown patches at Muizenberg beach For the longest time, people thought these patches were caused by sewage pollution, but they are actually small single celled little plants, which come together and form really huge, dense patches, turning the water brown Do you support any marine conservation initiatives? And what does the organisation/s do? My passion has always been giving back to the community. Over the past few years, I have been privileged enough to be involved with various marine conservation organisations I volunteered for the Save Our Seas Shark education centre in Kalk Bay in my first year. Assisting with their maritime explorers' program This organisation and program introduce learners from underprivileged communities to the magic of the marine environment through surfing and snorkelling
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When or how did you get involved in scuba diving? Can you tell us about your first dive experience? When, Where and Why did you get into diving and freediving? My scuba diving journey started when I was 11 years old. My dad and I completed a Discovery Scuba Diving course together in Sodwana bay I fell in love with the underwater world right then At age 13, I joined my dad to complete our open water diver course together We have been dive buddies ever since I grew up going diving at Sodwana bay, surrounded by tropical waters and coral reefs, which was such a fantastic experience.
Centre and works as a Wildlife TV Presenter for Wildearth on DSTV channel 183 We tracked her down to ask her a few questions about her diving, studies, conservation efforts and motivation
I am truly blessed to have observed the underwater world from such a young age. This experience left me inspired to want to pursue a career studying marine biology As a first year student, I moved to Cape Town to pursue my dream of becoming a marine biologist. It is here that I was introduced to the beautiful kelp forests and where I started freediving I was an avid underwater hockey athlete, and it was my absolute favourite sport I had the opportunity to travel the world as part of the Junior Springbok team through the sport I have been to Spain and Australia, diving along the way. Freediving has opened the doors for me to share the underwater experience with friends who aren't scuba divers. Anyone can freedive and experience the beauty of our oceans, and it's as simple as putting on a mask and snorkel and taking that first step into the sea.
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By teaching them why it is essential to protect our oceans, they would hopefully want to take the message and share it with their friends and family I couldn't have been more stoked to get the opportunity to work for the SOSF Shark Education Centre as their social media consultant I get to share the fantastic surroundings of our oceans and work with the kids from the various programs I used to volunteer for in my undergraduate studies. Do you have a diving bucket list? And why do you want to dive the destinations or experience the dive sites? Being a marine nerd, my bucket list consists of creatures rather than places. For years I have wanted to see a whale shark, and last year my dream finally came true! I had the opportunity to swim with these gentle giants in Mozambique Some creatures still very high on my bucket list include the Thresher Shark, Basking Shark, Weedy Scorpion Fish, Knysna Seahorse, and the White Shark. Tell us about your motivation behind "Mermaid Danii" and your underwater photography? Are you inspired by any renowned underwater photographers, and who?
underwater world for themselves encourages them to want to protect it. People won't protect what they don't love, and they won't love what they don't understand
The ocean is such a big part of my life, and with scuba diving, freediving through the kelp forest, photography, marine biology, and education, I wanted a way to combine all my passions. So I started my own dive school, Capensis Diving Capensis is Latin originating from the Cape, where my love for teaching grew I recently created my own underwater photography course, which I am incredibly proud of The course gives divers the tools to capture their own underwater images and share them with their friends and family. Ultimately, I want to help create better diversity for the blue, so those that fall in love learn to protect it. What is your favourite Western Cape dive site? And why? My favourite dive site in Cape Town, which might sound a bit cliché to the people who know this spot, is definitely Windmill Beach. It's right next to Boulders beach. The reason is that it is one of the places I have dived the most in Cape Town It's where I take all my friends who have never dived, or freedived before, to just get in the water and experience diving in the kelp forests This place is really close to my heart, it is really protected and shallow, and there are always loads to see, from octopus, nudibranchs, seals and even penguins if you are lucky. Are you a DAN member? And what does DAN dive cover mean to you? Yes, I am a DAN member. It is essential to know and be reassured that when I am diving somewhere across the world or doing a course in Cape Town, my students and I are in safe, reliable hands. Someone who appreciates DAN's cover even more than me is my dad, who doesn't always enjoy his little girl diving halfway around the world So, it definitely gives him peace of mind ADL
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The most important thing to remember is that if you see that you cannot control the dive conditions and don't know if you are up for the challenge, call the dive You can do so before or at any time during the dive
Most of these scenarios are predictable, but low visibility becomes tricky when a diver is unprepared. Touching down on a muddy bottom upon entry or one wrong fin stroke or hand movement in a silty, easily disturbed environment can put an end to what visibility you have
Low-Visibility Diving Weather, silty sediment, time of day, or water movement are just a few natural factors among the range of possible causes that can influence the visibility at your dive site. Low visibility diving can be pretty enjoyable, but it depends on the circumstances and comfort level Why do people dive in low-visibility environments? Some divers, such as public safety divers, might have to venture into low visibility situations Recreational divers may have no clear water nearby but want to dive regardless Searching for fabulous treasures, such as blackwater diving for megalodon teeth, is adventurous, even for experienced divers Some creatures only come out for the critter hunters to see when it is dark or when the sea is more disturbed than comfortable
RESEARCH, EDUCATION & MEDICINE ADVANCED DIVING
What is the worst thing that could happen? It can be a fun experience to dive without seeing anything. When you need to rely totally on your ears and hands, you will be surprised by how quickly your body can adjust to a new situation If you have little or no experience in poor visibility but must suddenly deal with it, it would not be surprising for panic to set in A complete loss of orientation, however, can be alarming Panic is among a diver's worst enemies and can ultimately lead to death in a rare worst case, but it is something you can overcome through preparation and training
By Frauke Tillmans, Ph.D.
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How can we deal with bad visibility?
After a separation incident, buddies are less likely to find a diver dressed in a black suit, hood, mask, gloves, and fins Bright colours are a safe asset in low visibility. Follow your agency's recommendations if you lose visual contact with your dive partner. These procedures usually include carefully searching in this case, with all your available senses for one minute before surfacing to reunite the team. While you search, remember that you are in a 3D environment and cover all directions A spool or reel can be helpful in safely finding your way back to where you came from if you know how to deploy it and reel it in without making a mess Cavern or wreck diving classes will teach you how to use a reel or finger spool You do not have to start cave diving to benefit from the skills an entry level overhead environment course can give you When you expect limited visibility, go over some additional communication signals with your buddy Signals using light or touch may be the only way to communicate.
Disorientation: If you get disoriented whether it's being unable to remember the way back to the boat's downline or trying to use your bubbles to orient yourself to the surface in a silt out you should be able to rely on your predive preparation Research everything about the dive site before getting in the water. Learn where there are points you can reference during your dive; if you are wreck diving, for example, memorize how deep the wreck lies and at what depth the anchor line is attached. Know that you are on the way back when the wall is on your left shoulder and not your right; remember which direction you went from the entry, or use a
Tools: If you know that visibility will be poor when planning a dive, make sure you have the right gear and the confidence to use it. This equipment may include underwater lights, a strobe light, a surface marker buoy (SMB), spools, a reel, and a compass Lights can help in low visibility, but they can also worsen some conditions If particles and disturbed sediment are abundant in the water, a light will illuminate those particles, which can be bright and make it harder to see where you are going You might need to angle your light downward rather than straight in front of you and reduce the light intensity. A strobe light is a good option for marking an entry or exit point in low visibility It might also be a way to mark yourself by illuminating your tank so your buddy can more easily spot you if you get separated
Lines: Public safety dive teams combat low or no visibility with a tended line, but that is not a valid option for a sports diver without the necessary training. Using lines, however, is a strategy that all divers can employ A buddy line is an option for two teammates who do not want to get separated. Buddy lines are relatively short ropes short enough to limit entanglement but not too short to prevent movement connected to your gear with carabiners or by slipping a loop around your wrist
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compass to navigate back. If you become disoriented during an open water dive and can't safely determine which direction is home, make sure you have the means to signal your location to the surface crew Separation, signalling, and retrieval procedures should be part of every safety briefing. You should be able to deploy an SMB for an unplanned ascent safely If a current is present and you have the opportunity and know how to, you might want to attach the SMB to the wreck or dive site and follow that line up to ensure you do not drift farther away Whatever happens, make a safe ascent, and do not violate your ascent or decompression obligations You can deal with most problems at the surface. In an actual emergency that requires a rapid ascent, do it as safely as possible Don't ever worry about ditching nonvital equipment if you have to losing a spool, a double ender, or weights is much less of a problem than being lost at sea Mental preparation: The most essential tool you have in your kit your brain. Do your homework ahead of time, and mentally go through the dive before getting into the low visibility situation Review the safety procedures in detail with your teammates, and ensure everyone knows how to react. If your vision gets restricted, take a couple of sanity breaths, and start thinking about your options and strategy Knowing that you can safely make it out of a challenging situation will calm you, help prevent panic, and potentially lessen your risk of injuries that could occur with an uncontrolled ascent. Your comfort zone is entirely about you Are you comfortable in zero visibility? Will you ever be? What is it about this experience that some people love and want to do again and again? If you have not already dived in low visibility, it's worth trying at least once with someone who has experience It's almost meditative for some divers It will make you appreciate crystal clear waters even more. If you are still not convinced after trying it, nothing is lost. You can prepare for many of these situations by taking speciality courses. A limited visibility or night diving course, a cavern class, or an advanced wreck diving course will prepare you for some scenarios you might not have considered You can acquire some skills during the course, while the rest will come with practice and exposure The skills you learn will work for you in murky water and
MEDICAL LINE DAN Medical Information Specialists and Researchers Answer Your Dive Medicine Questions F R O M T H E
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Q | During dive training in the pool, I couldn’t breathe after clearing my mask with my regulator in my mouth After surfacing, I took six to eight wheezing breaths and then could breathe normally again. It is possible that I inhaled water during the exercise, but my instructor and I could not recall when or how that would have happened Someone at the training centre suggested that something might be wrong with my epiglottis. Is there a way to inspect the epiglottis to ensure it is functioning properly? What causes it to relax and open back up? It is not uncommon for new divers to have some anxiety when entirely removing their masks underwater When you expose your nose to the water, it’s natural to feel uncomfortable if water enters the nasopharynx. Our bodies are trained not to take a breath while underwater, but it is possible if you can relax and focus on breathing through your regulator If water entered the larynx, the epiglottis’ natural response would close the airways to prevent
aspiration. The larynx would reflexively trigger coughing to expel the fluid, or you would try to remove the fluid through exhalation Even a small amount of liquid can induce laryngospasm, stimulating this powerful reflex.
Ben Strelnick, NREMT, W EMT
This passage from Marieb and Hoehn’s Human Anatomy and Physiology is a good overview of how the epiglottis works: “When only air is flowing into the larynx, the inlet to the larynx is wide open, and the free edge of the epiglottis projects upward. The larynx is pulled superiorly and the epiglottis tips to cover the laryngeal inlet during swallowing Because this action keeps food out of the lower respiratory passages, the epiglottis has been called the guardian of the airways. Anything other than air entering the larynx initiates the cough reflex to expel the substance ”
A person’s preexisting condition and exercise intolerance will affect the heart and lungs’ ability to perform underwater Various factors while underwater lead to intravascular volume shifts to the central circulation involving the heart, coronary vessels, and lungs In a healthy state, this increase in fluid usually causes no problem Still, a person with pulmonary hypertension will struggle, sometimes even at rest, to keep up with the right ventricle’s increased workload to overcome the elevated pressure within the pulmonary vessels.
Pulmonary hypertension is considered a high risk condition, and diving is not recommended for anyone with this diagnosis Endurance activities such as diving, which are likely to pose the highest hemodynamic demands and require a high physical fitness level, are challenging for people with pulmonary hypertension The stress that diving puts on the lungs and the right side of the heart may be too much for such an individual. Concerns of congestive heart failure or immersion induced pulmonary oedema are just two significant risk factors
Q | Can someone diagnosed with pulmonary hypertension become a diver?
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Another possibility is that you had an anxiety induced laryngospasm, which can be triggered by discomfort, panic, or high anxiety. Some physicians think this spasm is part of the body’s natural defence against accidental drowning or suffocation and may be part of the body’s response to fluid in the larynx. Your breathing problem may be an issue with your comfort level and experience, but there may be other complications we cannot identify based on the information you provided Discuss these concerns with your physician, and request a fitness to dive evaluation to ensure that you have no physical contraindications to diving activity. If needed, your physician may refer you to an ENT for further investigation If your physician clears you for diving, we recommend that you complete additional, rigorous pool time to work on skills with your instructor before proceeding any further in your training.
Shannon Sunset, NCPT, NREMT
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Diving may be possible for you, but whether it’s safe is not a quick and easy answer because there are many additional factors to consider regarding a concussion Given that your injury occurred a few weeks ago, it is still too early in your recovery to give specific return to dive recommendations. Suppose you experienced a loss of consciousness (LOC) that caused you to fall or that otherwise led to your concussion In that case, however, you should seek further evaluation to determine the cause of that LOC and if that condition is compatible with diving. The risk of seizures is one of the biggest concerns for determining fitness to dive after a head injury The recommended waiting period before returning to diving varies depending on the degree of damage, recovery period, and seizure risk. Return to diving is based on your symptom free recovery and evaluation by your physician team
The best recommendation we can make is that you focus on your recovery and not how soon you can resume diving. Seizure risk is the primary determinant after your head injury is necessary before consideration for a return to diving Once you are completely healed and released by your physician team for total, free activity, seek a fitness to dive evaluation with a knowledgeable physician in dive medicine before attempting to dive.
Q | I sustained a concussion a few weeks ago. When can I return to diving?
Anne Strysniewicz, AEMT, DMT
Question
The following are a few specific conditions to consider: Dilation and dissection of the aorta: Fluid changes while diving may stress the aorta Cardiac valvular conditions, cardiomyopathy, and dysrhythmias: These potential problems are often more significant if they occur underwater
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Thermal regulation: Wearing thermal protection can delay the core temperature drop from immersion in water, but you will eventually cool and self regulation may be challenging. You should review temperature regulation with your physician Medications and your baseline wellness are also worth reviewing Some medicines may have adverse reactions that may be a contraindication to diving Your daily wellness is a necessary consideration, as any regularly occurring pain or deficits may make diagnosing DCI difficult It’s essential to have an open discussion with your treating physician and follow their recommendations.
Pneumothorax: Marfan syndrome can have a higher association with pneumothorax There can be a risk of spontaneous pneumothorax (collapsed lung) with little or no inciting event. Although problematic on land, it is life threatening while diving Pulmonary barotrauma can cause a collapse of anyone’s lung Upon ascent, trapped air expands and may cause a collapsed lung to develop into a tension pneumothorax a medical emergency in which air cannot escape the pleural space around the affected lung; this leads to compression of the heart and the other functioning lung. Also, lung overexpansion can lead to arterial gas embolism, a potentially fatal complication Scoliosis: Spine curvature has been associated with Marfan syndrome Depending on the severity, scoliosis may cause a reduced exercise tolerance, making routine dive activities such as carrying gear, climbing a boat ladder, or swimming against a current more difficult that Marfan syndrome affects is an important consideration
I have Marfan syndrome and would like information from someone specialising in diving and its associated risks My cardiologist has recommended against diving, but people with Marfan syndrome usually have limited physical activity, so I was not surprised. I have been treated my whole life and maintain a very active lifestyle, including swimming, water polo, basketball, and marathon running, against all recommendations. What are the risks for someone with Marfan diving, and is there anything I can do to mitigate them? Marfan syndrome has an extensive spectrum of presentation from mild to severe and requires your physician team’s assessment. Despite the active physical activities that you describe, many factors may have influenced your cardiologist’s recommendation against diving Physicians will carefully separate the list of appropriate activities Diving affects various body systems, so the extra stress on systems
Spinal dura: There may be changes to the spine’s dura, resulting in pain and headache These changes may have a confounding impact on spinal decompression illness (DCI) diagnosis.
Robert Soncini, NR P, DMT,
Divers strive to safely optimise air consumption to allow for the possibility of more bottom time. Practising rhythmic breathing without breath holding can benefit divers Yoga is an excellent way to refine and maintain your ability to breathe rhythmically even during periods of physical exertion. Yoga and scuba diving share a similar peaceful energy and emphasis on proper breathing to maximise the quality of the experience. Ujjayi (oo jie yee), also known as victorious breath, is a breathing technique used in many yoga practices Ujjayi is performed by constricting the back of the throat slightly as you breathe in and out through the nose with inhalations and exhalations of equal length The breath constriction creates a sound similar to that of ocean waves or Darth Vader Using the ujjayi breath during yoga gives the practitioner a basis for monitoring the physical demand on the body: If the breath becomes strained, the practitioner can decrease the intensity to maintain smooth, steady and equal breaths. (This breathing technique should not be used while diving.)
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Here are five basic yoga poses to try while using the ujjayi breath. Start and end with mountain pose. To increase intensity you can add chair pose in between each pose All poses begin from standing
IMPROVE YOUR BREATHING
P R
By Kelli Cuppett A C T I S I N G R H Y T H M I C B R E A T H I N G W I T H O U T B R E A T H H O L D I N G C A N B E N E F I T D I V E R S
STRENGTH & FLEXIBILITY
To avoid an increased risk of decompression sickness, DAN recommends that divers avoid strenuous exercise for 24 hours after making a dive. During your annual physical exam or following any changes in your health status, consult your physician to ensure you have medical clearance to dive
DIVE FITNESS NOTE
Yoga can yield a healthier mind and body
Consistent yoga practice can improve strength and flexibility and can yield a healthier mind and body. Using the ujjayi breathing technique during yoga can teach divers how to control their breathing, so that when they enter the water, they can maintain rhythmic breathing despite their physical exertion To embrace the full benefits of yoga practice, find a yoga studio or registered yoga teacher. Always consult your physician before beginning any exercise programme or changing your physical activity patterns danmedic@dansaorg
FOR DIVE FITNESS ADVICE EMAIL US AT?
3 Gaze forward or up at your separated hands. 4 Root into the feet (i e , balance your body weight between the balls and heels of both feet). 5 Stay here for five breath cycles Start and end your session with the mountain pose. Keep your knees over your ankles when doing the chair pose.
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2 Contract your thigh muscles to pull up the knee caps 3 Descend the tailbone (i e , subtly rotate the pelvis to point the tailbone toward the ground, lowering it slightly), draw the navel to the spine, and relax the shoulders down the back, away from the ears. 4 Gaze forward Distribute your weight equally between the balls and heels of both feet. 5 Stay here for 10 cycles of ujjayi breaths
Keep the knees over the ankles and not forward of the toes. The legs can be touching or hip distance apart 2 Descend the tailbone to release arch in the back, and bring your arms over your head in line with your ears
1 Bend your knees as if to sit in a chair
MCHAIR OUNTAIN 1 Stand with your feet hip distance apart (or with feet together and big toes touching).
I
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D V E F I T N E S S
WARRIOR 1
The Warrior 1 pose requires you to bend one knee 90° and raise your arms overhead.
1 Take a big step back with your left foot The foot should be turned out slightly and pressed firmly into the ground 2 Bend your right knee 90 degrees to bring the thigh parallel to the mat, and keep the knee over the ankle Engage the quadriceps of the left leg, and press into the right foot. 3 Sweep your arms overhead, shoulder distance apart, relaxing the shoulders down the back, away from the ears 4 Gaze at the thumbs or forward. 5 Stay here for five breath cycles Repeat on other side
WARRIOR 2
1 Take a big step back with your left foot, placing it perpendicular to the right foot. The instep of the left foot should be in line with the heel of the right foot 2. Bend the right knee 90 degrees, bringing the thigh parallel to the mat and keeping the knee over the ankle. Engage the quadriceps of the left leg, and press into the right foot and the outer edge of the left foot
3. Extend the arms parallel to the ground (right arm forward and left arm back) in line with the ankles Reach through the fingertips of each hand, and relax the shoulders down the back, away from the ears 4. Gaze over the middle finger of the right hand. 5 Stay here for five breath cycles. Repeat on other side. For the Warrior 2 pose, extend your arms parallel to the ground in line with your ankles. E F I T N E S S
D I V
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4 Place the right forearm on the right thigh, and extend the left arm over the head. Rotate the chest toward the sky
1 Take a big step back with your left foot, placing it perpendicular to the right foot
5 Stay here for five breath cycles Repeat on the other side.
2 Bend the right knee 90 degrees, taking care to keep the knee above the ankle and not forward of the toes.
3 Press into the outer edge of the left foot, lifting the left arch Engage the quadriceps of left leg, and press into the right foot.
SIDE ANGLE
Extended Side Angle pose stay here for five breath cycles. Repeat on the other side.
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As an undergraduate, I was in a dual biology and geology major program for some time I chose geology because it was the entry into taking oceanography courses, and I was really focused on that. I was determined to be a marine biologist, which was very popular at the time A faculty member in the department of microbiology at the medical school was doing high pressure research. I approached Robert Marquis, the head of that group, and he embraced my interest and accepted an unknown undergrad as a volunteer in his lab.
My medical specialty is emergency medicine My doctorate in microbiology was specifically in microbial physiology, where my focus was high pressure gas physiology. I studied the effects of high hydrostatic pressure and various gases oxygen and the entire array of noble gases on various microorganisms. That was probably my start in studying things related to dive medicine Were you interested in diving before you got involved in this line of research? Are you a diver?
What Does It
Based on biochemical observations, my work demonstrated that so called inert gases such as helium, argon, and others are not actually biologically inert We sort of already knew that in terms of the theory on narcotic mechanism, meaning insertion of these gases into membranes and proteins My work showed that these gases also generate oxidative stress, and we’re still using that principle in some of our research
I never looked back I still do both kinds of work I get to switch from basic science in the lab one day to being an attending physician in the emergency department the next, and I’m delighted with how things have worked out What was the main takeaway from your Ph.D. thesis?
It is clearer now than back then, but we still have questions. The major question is simple: So what? What does that really mean in terms of diving mammals, animals of all kinds, and humans? I do not have an answer yet; we’re still working on it
mean?
Interview by Frauke Tillmans, Ph.D.; photos courtesy of Stephen Thom A professor of emergency medicine and researcher at the University of Maryland School of Medicine, Stephen Thom holds medical and doctorate degrees from the University of Rochester He previously led various clinical programs, including hyperbaric and emergency medicine, and a research lab at the University of Pennsylvania What is your academic background?
One thing led to another, and Marquis later became my thesis advisor, and the research I did with him became my main interest.
Yes, this goes back to my junior year in college. The only certification available in upstate New York at the time was through the YMCA, so that’s where I got certified I really enjoy diving, but it’s been quite a few years since my last dive. These days I don’t get many chances to dive, but I still go when I have the opportunity for cushy diving with great visibility and something to see underwater. How did you get started with dive research?
When I was a senior in college, I was undecided if I should stick with my research interest or pursue medicine. Marquis looked at me and said, “Well, Steve, we have a combined M D and Ph D program here ” Naive undergrad that I was, I gave him a puzzled look and asked, “So I don’t even have to choose?”
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STEPHEN THOM STUDIES THE ROLE OF MICROPARTICLES IN DCS AND OTHER CONDITIONS.
R E S E A R C H P R O F I L E I get to switch from basic science in the lab one day to being an attending physician in the emergency department the next, and I’m delighted with how things have worked out.
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We are investigating how this trigger effect works on a biochemical level in the model We started to collect blood samples from humans to see if we could prove the same mechanisms. These humans have ideally experienced high pressure in hyperbaric chambers, but we also want to study open water divers and those suffering from DCS. We hope to get more information about white cell activation and immune responses with samples from all over the world.
You have previously worked a lot with microparticles and helped revolutionize our understanding of the connection between inflammation and decompression sickness (DCS) Can you tell us more about that?
The University of Maryland recruited me as a professor for emergency medicine and to run a research laboratory The university promised I would have very little administrative work and a modest clinical commitment, which sounded amazing after I had simultaneously worked multiple jobs in emergency medicine and research for years. I now have a lab with a staff of three: a research assistant who is a lab technician, a research associate who is also junior faculty, and a postdoctoral researcher. We currently have a National Institutes of Health grant to study vasculogenic stem cells, which are the cells that make new blood vessels. That is a clinical focus mainly for diabetic wound research On the diving side, we have several grants from the Office of Naval Research, one of which involves central nervous system responses to high pressure We study the glymphatic system What is the glymphatic system?
We’re moderately smarter now than we were a few years ago in terms of what I call the bad actors Many microparticles are part of normal human health, and only a subset seems to cause injuries
We have published several papers on microparticles and recently have been hopeful that we can advance our understanding with a new project.
Until a few years ago, it was dogma that the brain does not have a lymphatic system like the rest of the body. That idea didn’t exactly make sense, but it’s what the data said. It’s now clear and demonstrable that this notion was wrong There is indeed a circulatory system for fluid other than blood in the brain that supplies brain tissue with nutrients and removes waste products That system is now called the glymphatic system a lymphatic system dependent on glial cells. We are looking at the glymphatic function in a model and how it responds to gases under high pressure, just as would occur while diving.
Microparticles are micrometer sized vesicles shed from the surface of cells They contain membrane and cytoplasmic constituents from their parent cells Rather than just being cell or vessel wall debris, however, they also function as signaling and transport molecules High pressures of inert gases such as helium, nitrogen, and argon can trigger inflammatory microparticle production
Tell us more about your current work
I think the microparticle story is not restricted to dive physiology. In 2009 or 2010, when I wrote my first grant on microparticles, you could read the world’s literature on microparticles in an afternoon Now it would take months to read the tens of thousands of papers about the many disorders that involve microparticles Like with DCS, there are questions about whether microparticles represent the cart or the horse, and this seems to depend upon the particular disorder and many other variables We are doing some work looking at microparticles in diabetic studies, but the other big disorder at least in my eyes is carbon monoxide poisoning, which is very common. It is a major problem worldwide and is another area where a role for microparticles evolved very slowly
I accept that many people don’t like the notion that microparticles may be a central element of DCS and that we have not definitively proven that to be the case All our work, though, supports that they play a role We keep trying new angles, considering that maybe we’re wrong and it doesn’t play a part, but we always end up understanding that the theory still holds. This research, which my group has put together over a decade, has me thinking more and more that we have an answer Many in this field are married to gas bubbles’ role in decompression, which does not concern me One element of the gas bubble hypothesis for DCS fundamentally comes down to the bubbles’ nucleation site. From mathematical models going back to the 1960s, the conclusion is that the nucleation site has a half micron radius that is, perhaps coincidentally, the size range of a microparticle Those who don’t agree with me when I say that DCS is an inflammatory disease will probably be upset about this line of research.
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EDUCATION & MEDICINE
RESEARCH,
Research Profile DCS is one pathological scenario. Our view is that high pressure exposure is physiological stress, which is important to distinguish as profoundly different from damage I’m not saying that you are hurting yourself simply by diving Divers put their bodies in a stressful environment, and the microparticles are a response For all we know, some of them may be good for you and will not normally hurt you, but as with most things in the extreme, they can injure you if they get to that point. What was first: the bubble or the microparticle?
Some years ago we also showed that a subset of microparticles formed in response to high pressure has a gas phase that could hypothetically be a bubble nucleation site. Therefore the question becomes whether gas bubbles are an epiphenomenon for microparticle formation Where do you see your research heading in the next 10 years?
What do you do in your free time? I like to kayak, and I create stained glass windows and lamps in my off time, but it really comes down to spending more time in the lab Is there anything else you want our readers to know? It has always been incredibly helpful to connect and collaborate with other scientists and groups. If anyone has the means to safely draw blood from divers any kind of diving: recreational, provocative technical, scientific, or anything else before and after a dive, we are always looking for subjects to add to our studies. Safely collecting blood in this context means having an ethical protocol that an institutional review board has approved I would be delighted to collaborate with anyone interested. ADL
The more we look, the more we find that microparticles seem to be driving carbon monoxide injuries systemically and, most important, in the brain And now we find that glymphatic dysfunction in our carbon monoxide model is alarmingly prevalent. That is what our next grant, should we receive it, will cover We are comparing our models with carbon monoxide poisoning and DCS. The exact same events occur, showing similar mechanisms with the same secondary messenger systems and inflammatory pathways There are brain to blood and blood to brain communications. These connections also seem to be a factor in another of my emergency medicine interests: traumatic brain injury The other project comes from the significant questions I posed earlier: What does all this mean, and how does it help the dive community? With all the new knowledge, can we do something besides treating somebody with DCS in a chamber?
There’s still a lot to be done
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Hyperbaric treatment may not always be available We are looking at pharmaceuticals that can reverse or at least suppress the insult related to microparticles and the inflammatory responses. Many agents none of them available in your local pharmacy work in the model One of these agents, which we have already shown to work in the model, is now approved for investigation in humans with several kinds of infections but not yet for dive injuries Those who don’t agree with me when I say that DCS is an inflammatory disease will probably be upset about this line of research If you can accept that statement, however, there are a lot of potentially useful pharmaceutical agents that are worth investigating as a prophylactic or even therapeutic measure
By Christine Tamburri and Jim Gunderson
Divers who practice situational awareness are more likely to prevent a potential accident. It could be as simple as noticing a broken mouthpiece zip tie while gearing up or as complex as a panicking diver out of breathing gas.
Butch
Diving inherently carries an elevated level of risk because humans cannot survive underwater without specialised equipment An effective rescue is vital for a favourable outcome when things go wrong Most rescue diver courses teach students basic techniques to apply after something goes wrong, but better courses also provide strategies to prevent incidents from occurring in the first place.
“Everything
WHEN SHOULD THE RESCUE BEGIN? R E S E A R C H , E D U C A T I O N & M E D I C I N E
SAFETY 101
Mastering the art of awareness is not a simple task, and it can take divers years to become proficient at spotting potential problems you see is telling you a story. Are you listening?” Hendrick Lifeguard Systems
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At the Dive Site or on the Boat Other potential problems may only become apparent once the divers arrive at the site or board the dive boat Watch closely as the divers assemble their gear. Was the assembly process smooth and efficient? Were the divers confident? Did they make any mistakes? Please pay attention to divers who obsess over minor details; this behaviour could indicate insecurity in their ability to prepare for the dive properly
So when should the rescue begin?
It is also essential to listen to others’ conversations Questions and comments from divers can give insight into their experience and training. Listening can help you learn important information and prevent egos interfering with safety
Every diver should regularly practise rescue skills, but their goal should be to prevent incidents, so they never have to use those skills. Being an aware diver is often about identifying and solving problems before they become emergencies Deliberate observation can help make a dive incident and accident free by recognizing potential problems at each dive phase
In the Parking Lot Dive planning includes seeking to correct any issues that could cause potential problems When divers arrive in the parking lot, they should pay attention to what might go wrong to avoid it. How are the other divers acting? If those individuals are friends or acquaintances, pay attention to any unusual behaviour Is the ordinarily talkative person suddenly quiet? Does the typically confident diver appear anxious? Talking to the nervous diver may reveal their difficulties or safety concerns.
Please pay attention to the gear condition that divers remove from their vehicles Appearance isn’t everything, but it can indicate how often a diver is in the water or how well they maintain their equipment. Well used gear could suggest an individual who dives frequently or neglects their equipment. Likewise, don’t assume that someone in well used gear or a technical configuration is a well qualified and competent diver. Conversely, a gear bag full of new equipment might suggest a diver newly introduced to the sport Ensure you and your buddy have training on the gear you will be using, especially if borrowed or rented and familiarise yourselves with each other’s equipment
During the Predive Check
Before the dive, evaluate how much situational awareness other divers display Are they paying attention to only the task at hand, or are they aware of what those around them are doing? Are they distracted from their preparation, or can they capably handle multiple tasks? Please take note of these observations as they could indicate the preparedness of other divers to manage future problems that may arise
A predive check is the last opportunity to prevent an incident before submersion. One of the worst things a diver can do is assume that simply asking “Are you ready?” before
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descending can replace a predive check. This practice results in divers not inspecting and testing equipment, reviewing hand signals, or finalising the dive plan Using an acronym or a physical checklist will help divers complete a thorough review
instinctively The regular practice could help a diver effectively manage an emergency. Proficiency with skills such as breathing without a mask or dealing with a buddy who is out of breathing gas builds confidence in the water
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Many divers also adhere to a three strikes rule. If any three things during your dive preparation do not go as planned, you should postpone the dive Strikes can include many things, such as a diver waking up late and rushing to pack the car or a ruptured O ring. If something feels like a difficulty at any point, count it as a strike In the Water After submersion, pay attention to how other divers handle themselves in the water What is their comfort level? Indicators of distress can include buoyancy issues, hand sculling, increased breathing rate, awkward body position, or constantly holding the regulator to keep it in their mouth. The beginning of descent is the final opportunity to address potential problems before they become full blown emergencies Distress can quickly escalate to panic. Divers may have rapid and awkward movements (like trying to climb a ladder), fast and shallow breathing, or enlarged eyes moments before panicking, which often leads to rejecting gear or bolting to the surface Swift, efficient, and effective responses are necessary to prevent the situation from escalating to a more dangerous or potentially deadly scenario
Consistently practising rescue techniques is key to making every dive incident and accident free, and the art of awareness is a skill that divers should constantly utilise. Identify issues before a rescue is needed. Everything you see is telling you a story Are you listening? ADL
It is essential for divers to regularly practice in water rescue skills to know what to do if an incident happens
A rescue begins in your first dive class when you start to learn and develop the skills you need When a diver becomes proficient at executing basic skills in open water, they are more likely to respond effectively and capably to an emergency Divers who are confident in their abilities can focus less on themselves and more on those around them. Practising situational awareness allows them to recognise when other divers encounter issues and intervene to prevent emergencies
When a diver can calmly deal with issues, those situations become more of a nuisance than an out of control emergency. That doesn’t mean they won’t have to address a dangerous situation or terminate the dive, but they will be able to do it smoothly and efficiently
E R
René Coetzee F R O M A D A N M E M
R E V I E W
Just like so many other divers across the world, my experiences with customer service at DAN has been superb If it wasn't for DAN Southern Africa, a diver friend of mine (not diving at the time) would have died having miscarriage while visiting us in Mozambique in 2009 I'll never forget how DAN's doctors carried us through the night telephonically, instructing us what to do, what to check, until the border opened and an ambulance could take her to hospital. This wasn't even a dive incident, but DAN stepped up. Thank you DAN! B
Complacency often takes over in most cases, as hoses are sturdy and designed to be handled frequently and subjected to all kinds of abuses. But the risks never diminish, only our perception of risks
The keys to hose safety are regular inspection, competent use, and replacement according to the manufacturer’s guidelines Hose replacement is necessary with regular use and should occur more frequently with high usage or in humid areas where metals corrode easily.
The DAN Risk Assessment Guide for Dive Operators and Dive Professionals, which is available as a free download on DAN.org, contains a series of recommendations to address these risks This information
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When we first learn the basics of high pressures in hoses and cylinders, we are aware of the potential for serious injury to ourselves and those around us. If hoses fail, the results can be ear shattering sounds, parts as projectiles, or an escaping gas stream that is strong enough to take out an eye. Without suitable restraints, hoses can whip around with sufficient force to amputate a limb
High Pressure Hoses
By Francois Burman
PEOPLE WHO HAVE FILLED scuba cylinders, refilled oxygen cylinders, or boosted a gas mix are familiar with using flexible hoses. Some hoses are covered with a durable rubber or thermoplastic jacket, while others appear even sturdier with a braided stainlesssteel mesh on the outside. Correctly specified hoses are rated to pressures of up to 6,000 psi.
Some key recommendations for hose safety include the following: Keep flexible hose lengths to a minimum. Using rigid pipes to reduce the length of flexible hoses is the best practice Hoses should not exceed 6 5 feet and should always be fitted with restraints at the attachment points on both ends Keep them away from occupied areas, and place long hoses in a protective conduit or covered channel Choose hoses with antiwhip characteristics and kink resistant materials suitable for high traffic areas, abrasive contact, and typical dive environments Their ratings should well exceed the maximum possible pressures generated by the equipment in use
It is difficult to provide an absolute requirement, but good practice is to either inspect and hydrostatically test all gas hoses or replace them every five years, depending on the manufacturer’s instructions Taking these steps will help you lower the risk of a serious accident. Hoses are usually designed for extreme use and are unlikely to fail if handled carefully, regularly monitored for condition, and replaced when they show warning signs of damage due to wear, corrosion, or excessively rough handling
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A key component is how the end fittings are affixed to the hose. Purchase hoses from reputable suppliers, and have an inspection of end fittings at the top of your checklist. Regular inspection of a hose’s condition and monitoring the competence of people handling hoses will provide greater safety assurance
relates to selecting materials and manufacture, hose installation and use, and inspection and maintenance
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This, unfortunately, kept me from experiencing the wide variety of underwater marine life subjects available to photographers. The juvenile Basket Star was photographed at Sterretjies Reef, Gordon's Bay, Cape Peninsula. This site is far enough offshore to be generally outside the eddy of low visibility that often occurs off Gordon's Bay However, it is still reasonably close to the launch sites and has good biodiversity and more rugged topography than most of the close offshore sites in the area. It is a large area and primarily unexplored. I used my trusted Canon Powershot G12 camera in the Canon WPDC34 housing and an Orca torch to light my subject This gave me the black light effect as the light meter was set on spot reading of the white area of the basket star
Nicolene Olckers
When I started diving in the early 1990’s, I said I would prefer not to dive in cold water
LOCAL PTALENT ARTING SHOT ALERT DIVER LITE | 56
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