HOW TO BECOME A BETTER DIVER?

from Perfect Diver Magazine 22 issue

by perfectdiver

AQABA IN JORDAN

tips & curiosities

HOW TO BECOME A BETTER DIVER?

Text Wojciech A. Filip

Photo Tomasz Płociński

A KNOWLEDGE CHECK AWAITS YOU AT THE END OF THE ARTICLE – DO IT TWICE: BEFORE AND AFTER READING THE MATERIAL!

Here’s the deal: by spending 15 to 30 minutes, you will improve:´

- your position underwater´

- buoyancy control´

- reduce gas consumption´

- increase rescue safety

Which gear element impacts almost everything we do underwater?

Our hero: The crotch strap – our gear’s most crucial piece of material

The crotch strap is a standard element of rigs that includea harness and plate, but it can be successfully used in manytraditional jackets.

The purpose of the crotch strap is to hold your gear onyour back in such a way so that it cannot move towards thediver’s head. In other words, whether your head underwateris directed towards the surface or the bottom, it cannot causeyour gear to shift.

In this article, we will separately discuss the impact of thecrotch strap on beginner and advanced divers. No matter howadvanced you are, I recommend reading the entire material, as many consequences of using the strap are common for all divers.

BEGINNER DIVER

You will feel safer on the surface, also at sea with higher waves Without the crotch strap or with one that is too long, when you inflate your BCD with gas, instead of “pulling” you as high as possible above the water surface, it will only move the gear up, while your head will remain close to the water. Correct crotch strap length eliminates the problem.

You will improve your buoyancy control

A properly adjusted crotch strap allows you to take any position underwater freely. You can stand on your head easily and use it to peek into a shipwreck or another interesting place :)

If your crotch strap is too loose, it will cause the entire gear to move along your back towards your head, preventing you from raising it. You will automatically start holding your breath, which will change your buoyancy. Shifting gear means shifting the weight, which in turn will impact your position (to maintain control, you’ll start falling into the unwanted “seahorse” position). With your head stuck under the gear, your orientation will be limited – you might lose contact with your team or miss any signs given to you. Buoyancy control is also related to the next item concerning gas consumption.

PROPERLY ADJUSTED CROTCH STRAP – HIGH, COMFORTABLEPOSITION ON THE WATER SURFACE.

CROTCH STRAP TOO LOOSE – LOW, UNCOMFORTABLEPOSITION ON THE WATER SURFACE

You will reduce your gas consumption

With stable gear positioning on your back, you should have no problem with raising your head and breathe more easily (see the advanced divers part to learn why getting rid of CO2 translates to lower gas consumption from the cylinder). The ability to raise your head freely at any time during your dive – this is the same movement you make to open up the airways when providing first aid; it makes you breathe effortlessly. Being able to control your position freely, open airway and the possibility to control the environment also translate into less stress and all this results in significantly lower gas consumption – even up to 30%.

Simply adjust your crotch strap properly.

If your gear shifts towards your head, you will lower your chin to the chest and partially obstruct the airway, increasing your gas consumption.

ADVANCED DIVER

Contrary to what you might think, it is most often the advanced divers and instructors who can be seen with their crotch strap loosely dangling or even missing.

Here are some less obvious problems that can be easily eliminated by adjusting the crotch strap properly.

Underwater and surface rescue

When transporting a diver inside a shipwreck, cave or in open water, we use the so-called “sandwich”, where the rescue diver is on the back of the rescued. During rescue we should keep the victim’s airways open. On the surface, whatever procedure we use, we should open the victim’s airways (tilt the head back), give a series of rescue breaths and make sure to avoid secondary drowning, which means we keep the airways open and the head above the water.

A crotch strap that is too long, when coupled with a non-standard regulator configuration could block the victim’s head in a position that would prevent the airways from opening (due to the victim’s gear shifting high up their back).

Rescue operation – oxygen poisoning victim. Even if we assume that during rescue it is enough to only minimally open the airways to prevent barotrauma and full respiratory action will be restored on the surface, an overly long crotch strap may needlessly complicate the rescue operation on the surface, preventing rescue breaths prior to removing the gear.

Transporting and stabilizing the victim is way easier when a properly adjusted crotch strap length prevents the gear from shifting towards the head and the head itself can be easily tilted backwards at any moment.

Stabilizing position and buoyancy control in multiple stage cylinders diving

During multigas dives with multiple stage cylinders, the diver should be able to assume the same positions as a OWD diver, still having a really good time. Think how many technical divers have you seen standing on their heads bejeweled with stage cylinders?

This is no joke. Such position is part of rescue operations in caves and some shipwrecks.

If the crotch strap has the proper length, it will stabilize the entire gear, preventing it from sliding towards the head, rapidly changing the trim, and the diver can easily change their position as they wish without the risk of loosing control. The more gear you have on you, the more important crotch strap adjustment becomes.

If the crotch strap is too short (DPV d-ring between the legs), then during diving with a DPV you may experience a sensation of your trunk constantly lifting, which is dangerous during DPV dives in confined spaces. Moving the d-ring to the diver’s belly will significantly improve the position. In many harnesses, this can only be achieved by extending the crotch strap, because the DPV d-ring is usually sewn and locked on the strap.

When doing boats dives with large 2×18 or 2×20 twinsets, fasten the waist strap after passing it through the crotch strap, leaving maximum freedom until you get into the water. This is because large sets with the appropriate crotch strap length prevent you from seating comfortably on the gear bank with your gear on. Leaving your belly strap only loosely secured for the time when you are getting prepared for entering the water is very helpful.

Fasten the strap before entering the water!

PHOTO OF THE AUTHOR DURING A MANY-HOUR DECOMPRESSION AFTER DIVING ON “HMHS BRITANNIC”

Gas consumption and inert gases narcosis

The more complex the dive, the more important unrestricted breathing becomes, and its control largely depends on CO2 retention. An increase in CO2 level not only increases respiratory rate and the associated gas consumption, but also the risk related to a more “dynamic” course of inert gases narcosis. Increased CO2 levels may accelerate oxygen toxicity. Looking straight ahead, or keeping your head high up, causes the airways to open, which translates to increased safety at every stage of the dive.

HOW TO ADJUST YOUR CROTCH STRAP? A more detailed description, with photos and additional information, can be found in the article “Harness adjustment” in Perfect Diver issue 9 – just click and print the material you are interested in:https://issuu.com/perfectdiver/docs/pd_9_issue/68

KNOWLEDGE CHECK :)

It is important to understand that proper length means neither the shortest nor excessively loose crotch strap. After reading the entire article, read the following list and try to answer the question: “why does this happen?”.

I encourage instructors to perform a similar analysis, extended with very precise but easy to understand explanations you may give to your students during your courses.

An excessively long crotch strap may cause: ´

- increased gas consumption ´

- “seahorse” position ´

- problems with opening up the airways during rescue ´

- difficulties in swimming backwards ´

- increased levels of inert gases narcosis ´

- assuming a position with lowered knees