CAVE PLANING PART 1

TEXT FROM THE GUE PUBLICATION DEEP INTO CAVE DIVING WITH CONTRIBUTIONS FROM KIRILL EGOROV, JARROD JABLONSKI, DANIEL RIORDAN, FRED DEVOS, TODD KINCAID, & CHRIS LE MAILLOT PHOTOS KIRILL EGOROV, KATY FRASER, FRED DEVOS & RICH DENMARK

The rewards and hazards of every overhead venture require that dive teams develop a comprehensive yet flexible dive plan well in advance of the first tie-off. In contrast to what the term might suggest, dive planning entails much more than just establishing the intended path of a proposed dive.

The ensuing discussion is intended to help cave divers identify certain key elements in dive planning and logistics. A grasp of these key elements will greatly enhance one’s cave diving experience with additional safety and efficiency. When preparing for cave dives in unfamiliar environments, divers should combine the information found here with personal experience, common sense, and the advice of local authorities.

The nature of cave dives demands that teams cultivate a meticulous yet flexible dive plan well before entering the water. Dive teams equipped with such plans are in a much better position to deal with unexpected challenges, prevent small problems from escalating into serious ones, and enjoy their dive experiences. Research, logistics, physical training, testing equipment, reviewing emergency procedures, and finalizing the dive plan prior to entering the water will all help prevent most problems.

Prior to the trip

Before discussing planning criteria, it is important to acknowledge that regular maintenance doubles as dive planning. For example, divers who are careless with gear maintenance could experience numerous problems on a dive trip and may be isolated from easy repairs, ultimately ruining an expensive trip and/or leading the team into a dangerous situation. Divers should also be wary of conducting maintenance on all their equipment immediately prior to a diving trip. Equipment needs to be serviced on a regular schedule, and diving recently serviced equipment on less intensive dives rather than on big dives or diving excursions is advisable. Likewise, it is important for divers to maintain a healthy lifestyle with daily fitness as a normal part of their day. It is unwise to rush to get in shape by exercising rigorously and dieting a few days before an important dive if personal fitness and a healthy diet have not been a part of one’s lifestyle. In fact, sudden changes to a person’s routine are likely to cause more problems than they solve. Therefore, an active diver is best served by creating a lifestyle that supports an ongoing health and fitness routine as well as a set of habits that supports consistency with diving skills and equipment maintenance.

The first step in organizing a particular cave diving trip is to gather information. Let’s assume a cave diving team from the United States wants to go cave diving in Mexico. What kinds of things should they consider? First, what sites will they dive? Those around Merida where the caves are deeper, or those around Tulum where the systems are shallow and allow for long penetrations? Assuming that they decide on the cave systems around Tulum, they must then begin to gather relevant information. Which season is the best for diving these systems? What types of lodging are nearby and available? Do the divers have the correct devices for recharging batteries? Is the dive planned near a dive shop that can fill cylinders? Where can the divers rent cylinders? What kinds of transports are available? How many divers will the transports carry, and how much will it cost? Is there insurance? Can they pay by credit card? What kind of food is available? What is the water temperature? Do they need a wetsuit? A drysuit? Are heated undergarments, dry gloves, and heated glove liners needed? What kind of spare parts can they find locally? What can they rent? What must they bring? DIN adaptors for Yoke systems? Steel backplates or V-weights for twin AL80s (the local standard)? Which light and battery technologies are being used and what burn time does a given combination of a lighthead and battery provide? Is a backup primary light required based on the planned dive duration? What kind of tools are needed? Where is the nearest recompression chamber? What level of experience is required by these systems? If divers who lack the requisite experience are included on the trip, is there anything else for them to do?

Plan the dive, dive the plan

Divers must answer these and many other questions before they’re ready to undertake a cave diving trip. Beyond securing suitable accommodations, ensuring that their transportation requirements have been met, and guaranteeing that all equipment, spare parts, and tool requirements are met, there are a host of minor details that can make or break a trip. Conducting the research and gathering all the necessary information before getting on the plane to Mexico, for example, can greatly help to ensure that the experience will be a truly positive one. Dive planning may vary from being a fairly simple task for a recreational dive to a complex planning and logistics exercise requiring months of preparation in an expedition diving situation. The time required for planning will depend on the objectives of the dive and the characteristics of the exposure. Irrespective of the duration of the planning, the basic rules remain the same. All dives should have a plan (developed prior to entering the water) and be conducted according to this plan. Often this is referred to as “Plan the dive; dive the plan.”

GUE divers plan their dives considering a range of aspects to support some of the world’s most efficient diving. Planning is not just about what goes on in the water; it should also include surface strategies. All dive plans should ensure that the team clearly understands the following topics:

• Team strategies

• Points of interest and enjoyment

• Procedures

• Logistics

• Dive profiles and parameters

• Potential risks and their contingencies

• Support (both in‐water and surface)

• Nutritional requirements

Arriving at the dive site

At a given dive site, cave divers should always conduct a general site survey. This will hopefully verify pre-trip information. During this survey, teams should verify entry points, water conditions, diving logistics, and emergency procedures. Furthermore, cave divers should choose entrances that are convenient and that provide a reduced risk of spoiling visibility or of damaging the environment. In addition, cave divers should choose a convenient location to assemble their equipment. Equipment is usually easier to carry when assembled and transported on one’s back.

As discussed in the previous section, dive planning should be completed prior to every dive. The three key components of diver readiness are:

• Pre‐dive preparation

• Building a dive plan

• Pre‐dive sequence (including quick dive plan review GUE EDGE)

Building a dive plan is more involved than simply writing down strategies for the dive. The plan incorporates activities like testing the equipment, preparing food and drink, understanding logistical requirements, and identifying and managing risks. Prior to entering the water (or while resting on the surface prior to a dive), divers use the acronym GUE EDGE to review the dive plan they formulated. This acronym provides divers with a distilled version of the dive plan.

Divers should aim to perform this final dive plan review just prior to submersion. However, once again, divers will need to be flexible and decide about where and when the review should be completed based on environmental factors. The plan can be reviewed while resting at the surface, dressing for the dive, or just prior to entering the water. By the time these reviews are complete, the team should have discussed the dive plan in detail, established the order of the team and each diver’s responsibilities, and verified that everyone is comfortable with the proposed dive.

Teams should remember that all dives must take into account the diver with the least experience and should avoid plans that fixate the team on a single objective as opposed to multiple goals.

Logistical complications

Goal-oriented diving is a reality not only in cave diving, but in most forms of diving; pretending otherwise merely prevents one from safely preparing for a dive. Even so, cave divers must avoid allowing goals from subverting common sense and from undermining sound dive parameters. They must always remain aware of their limitations and of the risks inherent in the projected dive. In cave diving, certain goals have come to characterize the nature of the dives themselves. Each one has its own method of safe execution.

The following addresses some specific logistical issues that impact safe cave dive planning. These should serve as illustrations of the critical process that works toward safe dive planning. However, specific conditions may vary from the particulars of a projected dive plan, and divers must remain cognizant of this potential disparity.

Flow conditions

Many caves contain a flow of water that may not be predictable from day to day or even from passage to passage. For example, tidal or marine caves vary from one time of day to another. This water may flow out of the cave or flow into the cave. In the former case it would represent a spring flow; in the latter case it would represent a siphon. Divers must always remain cognizant of flow conditions and of their direction, remaining aware that moving from one tunnel to another can create a sudden shift from spring to siphon conditions. Flow conditions can significantly impact diving parameters, such as gas consumed and the time required to reach the exit, and must be carefully factored in. Divers must always remain aware that flow is a constant and potentially dangerous variable in diving.

Gaps and jumps

Some cave dives require that dive teams travel along different, non-continuous, permanent lines to reach their objective. To safely perform such dives requires that teams install temporary guidelines that connect these lines. Once a dive is completed, these temporary lines are removed during a team’s exit. If marked and installed properly, these temporary lines create a continuous guideline to the main line, to the team’s primary reel, and to open water. Cave teams should carry these lines with them on spools that hold approximately 24 to 30 m/80 to 100 ft of line. When used to link the breach between the ends of two permanent lines (e.g., when crossing through a sinkhole and continuing), this line is called a gap. If the line is used to link the breach between the middle of one line and the end or the middle of another, it is called a jump.

The safe execution of a gap or a jump requires that the team leader first affix a line arrow to the permanent line the team has been following, at the site of the intended gap or jump, pointing in the direction from which they have entered. The team leader will then attach the spool line to the permanent line at the site of the line arrow placement, forge across the passage, and connect the spool line to the line in the side passage. The team should remain in visual contact so they may assist one another. Jumps that cover a short distance allow the leader to connect the jump while the team waits at the attachment point. During a long jump, members of the team must stay close enough to assist one another. Typically, these distances are on the order of about 3 m/10 ft and allow for easy visual contact. On the way out of the cave, the team leader, now traveling last, will pick up the reel with assistance from the diver just ahead of them.

Studying cave maps significantly enhances the team’s comprehension of the cave layout and helps visualize the navigation challenges they may encounter.

Cave diving is an activity that requires a significant amount of gear and equipment.

Traverse

When executing a traverse, divers enter at one site and exit from another. In a simple traverse, one tunnel with one continuous guideline connects two access points. In a complex traverse, multiple tunnels with multiple lines are used to navigate from one access point to another.

In executing a simple traverse, divers should begin on the spring side (swimming into the flow) and treat the dive as if it were a normal cave dive. Once they hit their designated turn pressure, they should mark the line with a non-directional marker such as a “cookie” to avoid confusing other teams. They should note their gas pressure and time and exit through their original entry point. At this time, they should not remove the primary reel they attached to the permanent line. Then, on a second dive, divers should enter from the siphon side (assuming negligible flow conditions) and begin their penetration into the cave system in the direction of their marker. If the team locates their original marker before they hit their turn pressure, they can pick up their marker and continue to the other exit where their previously placed reel provides them with a continuous guideline to the open water. At that point they should remove the spring-side primary reel, and then return to the siphon side to remove their other reel.

At the end of a traverse, gas reserves should register no less than one-third of a diver’s beginning gas supply. Also, decompression obligations should be accounted for, and bottles placed at appropriate locations which, in the case of a traverse, would be at both ends (in the event that the traverse cannot be complet - ed). Divers should also decide upon a contingency plan.

A complex traverse incorporating multiple jumps and gaps is a very advanced dive and should be undertaken only after the divers achieve a thorough familiarity with a given cave system, and only after they have amassed sufficient overall cave diving experience. Divers typically carry out at least one additional familiarization dive for each jump required during a complex traverse.

Circuit

In a circuit, the entrance and the exit point are the same. However, the challenge posed by a circuit is that a segment of the dive entails oneway travel. This means that, unlike most cave dives in which divers retrace their steps, in a circuit they do not. As in the case of a traverse, both sides of the circuit should be explored and plainly marked. Divers should begin a circuit by proceeding from one side of the intended path, marking locations, and installing the requisite spools, until thirds are hit. They should then mark their location with a non-directional marker, leave whatever guidelines they have installed in place, and retrace their steps. Then, on a second dive, once they reach the other side of the circuit, they should install the appropriate guidelines and continue ahead towards their marker. If they come across their marker before their turn pressure, they can pick up their marker and complete the circuit, removing spools and markers as they proceed. Of course, the more jumps or gaps required, the more complex and challenging the circuit. Again, at the completion of a circuit, gas reserves should register no less than one-third of a diver’s beginning supply. Also, decompression obligations should be accounted for and bottles placed.

The above examples represent common cave diving objectives and are offered here to provide divers with an outline of sound diving practices as well as with a deliberate approach framework. Cave diving objectives vary greatly, ranging from improving gas consumption to finishing a survey, executing a complex circuit, or exploring a new cave system. Yet, divers must identify what they hope to get out of their dives and agree that when a stated goal compromises their team’s safe return, it will be abandoned. Goal-oriented diving can increase a cave diving team’s risk if divers fixate on goals and ignore the safety parameters established at the outset. For example, divers who are intent on completing a traverse might ignore or cheat on their designated gas supply and place themselves and their team at greater risk. While diving objectives are a common, if not mandatory, part of cave diving, they must be kept in perspective and not allowed to overshadow the primary objective: a safe return to the surface.

“A complex traverse incorporating multiple jumps and gaps is a very advanced dive and should be undertaken only after the divers achieve a thorough familiarity with a given cave system, and only after they have amassed sufficient overall cave diving experience.

The use of properly marked stage cylinders and strict adherence to gas switching protocols are essential for ensuring safe cave diving practices.

Risk identification

In life, few things are as subjective and relative to personal ability and preference as what can be defined as an acceptable level of risk. For some, the risks inherent in climbing Mount Everest are acceptable. For others, acceptance of such risks reflects nothing more than a death wish. Individuals, in all facets of their life, enjoy a wide range of permissible risk. For some, very little risk is acceptable, for others, the greater the risk, the more desirable the pursuit. One of the most important aspects of planning a cave dive is properly defining risk, yet this essential component is often ignored and usually undervalued. Once a cave diving team has established its diving objectives, it must gauge the degree of inherent and artificial risk linked to the planned excursion.

Inherent risk identifies the dangers that are inseparable from the activity pursued. For instance, cave diving requires individuals to recognize that a direct ascent to the surface is not an option, and that all dive planning must account for the added risk posed by the introduction of an overhead barrier. On the other hand, artificial risks include risks that result from the behavior of cave divers themselves or are inherent risks that are not properly managed by the dive plan.

For example, the inherent risk of overhead diving can be addressed with proper training, the proper use of guidelines, team diving, responsible breathing gas limitations, proper equipment, and a sensible dive plan. Alternatively, this risk becomes amplified by improperly addressing these components. Very often, cave divers are their own worst enemies with respect to the danger of any given dive.

Gases and risk

Few cave divers invest the requisite energy or thought into assessing the inherent risks of a given dive. On the contrary, they are often oblivious to them. Consider, for example, industry standards for labeling diving cylinders containing mixtures other than air. Divers are asked to clearly label their cylinders with markings like NITROX or TRIMIX. The assumption here is that the primary risk lies in the use of these gases. This is, in fact, untrue. In reality, the gas mixtures themselves present no risk; the risk exists almost entirely with the depth at which these are used. One nitrox mix might be used safely at 21 m/70 ft, while another might be used safely at 30 m/100 ft. However, a 21 m/70 ft nitrox mix, if used at 30 m/100 ft, would possibly result in an oxygen seizure and a fatality. In this situation, and many others like it, the misidentification of actual risk not only fails to reduce risk, but also actually amplifies it. To reduce the risk of misidentifying various breathing mixtures, divers should label the maximum operating depth of the mixture utilized.

Domains of risk assessment that commonly lead to problems include, but are not limited to, the following: solo diving, improper guideline use, violation of the rule of thirds, improper use of gas mixtures, inefficient use and placement of diving equipment, complacency around CNS oxygen toxicity, poor recognition of the value of proper experience and/or training, and sloppy management of contingency planning (ranging from separation to inadequate breathing supplies). Some of these variables even become risks as a result of divers seeking to protect themselves against irrational fears; in fact, such desires can actually create the conditions for the emergence of a legitimate threat. For instance, divers may have an irrational fear of decompression sickness; this could lead to the misuse of high oxygen mixtures, inordinately long decompressions (which can expose divers to hostile environments), or the misuse of too many decompression mixes (creating greater oxygen risk and task loading). Improper dive planning or contingency arrangements might also leave divers stranded at sea and/or without sufficient breathing supplies.

Teams

Another key element of risk assessment is identifying individuals who share comparable levels of awareness, motivation, risk acceptance, and diving proficiency. This is because a short cave penetration can be more perilous for cave divers with limited skill than a complex cave exploration would be for divers with refined skills and experience. Cave diving, like all diving, has an element of risk. This entails that cave diving teams identify the inherent risks of a dive and strive to reduce unnecessary ones. In most cases, cave diving can be enjoyed at a very low level of risk. However, poor diver proficiency, bad planning, and the careless use of advanced technology, among other things, elevates that risk.

The risk of a particular cave dive usually has less to do with the dive itself than it has to do with the planning, ability, and experience of the participants. In other words, cave divers generally create their own problems by not properly identifying or managing the risks of a particular dive. Learning realistic risk analysis is the single most important component of proper cave dive planning. It is impossible to craft a realistic and safe dive plan without first identifying the actual risks of the proposed activity. While gaining experience with risk identification, cave divers are encouraged to list all possible risks and to rate these in terms of the degree of threat they pose to a diver’s life.

Proper cave dive planning should either reduce or eliminate risk. Measures that do not do so should be discarded, while emergency procedures and contingency planning should properly support risk that cannot be eliminated. Generally speaking, any unresolvable problem that arises from less than three failures (equipment or action) is not a properly managed problem. For example, a scooter failure would result in a diver being towed (one problem) while two scooter failures would result in divers swimming (two problems). If the distance to the exit is too far to swim (the third and irresolvable problem), then the team did not plan properly for this dive, and they should have towed a safety scooter.

NEXT TIME: DIVE PLANNING – Part 2