The Challenges of Stage Cave Diving

Psychological and Physical Considerations of Using Stages in Caves

Stage diving in caves refers to carrying one or more cylinders (in addition to doubles) for increased penetration distance. The diver typically breathes a portion of the gas in his stage cylinder(s), and then attaches it to the line and continues on with his doubles. Stage diving allows divers to see distant areas of the cave that few divers ever reach, and is one of the most popular advanced cave diving techniques.

Carrying one or more additional tanks on your cave dives seems easy, and many cave divers don't bother to take a proper stage diving course. However stage diving requires more than solid basic technics. It requires a diver to understand and prepare for everything that can go wrong with the stage and with his doubles, and to be capable of leaving the cave in the same amount of time and using the same amount of gas that he used to go in. Even in zero visibility and even with gear failures.

Safe stage diving also requires that the diver consider his limits from a psychological and physical perspective, as stage diving can easily take a diver out of his comfort zone in many ways. Reading this article is no subsitite for a proper stage diving course, but here is an overview of some of the psychological and physical considerations for stage cave diving.  

The Psychological Pressure of Being Really, Really Far From Your Exit

Stage Cave Diving
Vincent Rouqette Cathala drops a stage tank in the cave. Cyril Buchet

We also call this distance pressure. Cave divers carry stage cylinders to travel further into the cave, to visit places that are impossible to reach on a single set of doubles. It seems silly that the very reason for carrying the tanks may also be one of the main hazards.

Swimming the stages into the cave, dropping them, and continuing on may be easy and eventless. But the idea of being very far from the exit does lead to some stress, even for the most experienced of cave divers. Knowing that you are so far from air in the event of a gear failure or emergency situation can make the problem seem much bigger than it actually is.

The idea of swimming 1,000 feet out of a cave on a back up light is not terrifying to many divers, but the idea of swimming 5,000 feet out of a cave on a back up light may lead to self doubt and distracting internal dialog: When was the last time you changed the batteries? Will you make it before you lose all your light?

Far back in the cave, even a small problem can lead to increased stress, a higher gas consumption rate, and reduced focus, which of course, can lead the diver to make more mistakes and have more problems.

The best way to manage distance pressure is to push your limits slowly. Increase the distance you swim in bit by bit, and be sure that you are confident and comfortable with each increase in distance before you travel further in.  

The Psychological Pressure of Being a Really Long Time from the Surface

In cave diving, time = gas = life. All cave divers are acutely aware of this. Increasing your swimming distance means increasing your dive time, and the longer you have to swim to get out, the more stressful a problem or failure is, and the longer the diver must manage and control that stress.

Strong mental control is an essential quality of safe stage divers. They must be adept at managing problems, and confident in their ability to do so. Without this important mental attitude, problems on stage cave dive will often appear more daunting than they actually are, leading to reduced focus and the likelyhood of diver error, which will only exacerbate the situation.

Another consideration for stage dives is no-decompression limits. The longer your dive, the more likely you are to approach no-decompression limits.  A dive on doubles may not give a diver enough gas to get into deco at 70 feet. A dive with doubles and a stage almost certainly will.

Clearly, you are more likely to run up against deco limits on stage dives than on normal dives. On cave dives that expose the diver to decompression or the possiblity of decompression, long swims may lead to the additional stress of making it back to a decompression stop by a predetermined minute of the dive.

If a diver is delayed in exiting the cave, a long swim will give him plenty of time to watch his decompression time rack up on his dive computer. This can feel a great deal like losing control, even if the diver has carried adequate gas to get him through a longer than expected deco stop. 

Increase your dive times little by little, and plan your dive to limit decompression stops. Carry enough gas that you will still have enough gas to deco safely even if you exceed your dive time. Remember, you don't have to swim right up to your max dive time! Reduce your turn pressure, distance, and times until you feel comfortable and capable and confident.

Ability to Focus on Long Dives

One of the most difficult aspects of stage diving is maintaining focus through the entire dive. As distance and time pressure build up, and as the diver becomes fatigued, it's hard to pay attention to the details of the dive. But it's still essential – in fact it's even more important to stay on top of your game on long dives.

Traveling further into a cave increases the number of physical and visual references that a diver must remember. The longer the dive, the more navigational decisions such as t's, gaps, jumps etc the diver must make, and it's easier to make a mistake or become confused when exiting from a long dive.

Take care to keep your dive times and penetration distances within the limits of your ability to clearly remember your references. Any clue that your attention is flagging – such as poor passive communication, swimming past elements of the cave that you no longer remember from the way in, or mentally zoning out should alert you that you have passed your limits on this particular dive, putting you and your buddies at risk. Consider shortening your dives until you are comfortable with longer penetrations. Remember, your ultimate goal is not to break bottom time records, but to be 100% aware during the dive and to come out safely.

Push your ability to concentrate and remember references slowly. Increase your dive times and penetrations in short increments. Also, before enrolling in a stage course, be sure that you have practiced sufficiently that the command chain and cave diving basics become second nature, so that you are not using one-hundred percent of your brain on basic cave skills. Your focus should be on the new aspects of cave diving. For most cave divers this takes hundreds of cave dives.   

Getting Cold

Being cold makes paying attention to your buddies and the dive nearly impossible. As one of the main reason to use a stage in cave diving is to increase your bottom time, the thermal protection you chose for a stage dive will often be warmer than what would use on a normal cave dive.

Being slightly cold as you finish your safety or deco stop is not generally an issue, but if you are feeling even a little cold when you still have an hour to swim out of a cave, you may find yourself shivering or even close to hypothermia near the end of the dive.

As your body fights the cold, the energy you have available for swimming, thinking, and simply enjoying the dive is greatly reduced.

Physical discomfort tends to lead to loss of focus, much like a piece of grit in a shoe while running. At first it's not a big deal, but soon it is all that you can think about. As your awareness is diverted to thinking about how miserably cold you are, your you are no longer a safe diving buddy.

Being very cold on a dive also increases a diver's air consumption rate, leaving him with less gas available in an emergency – an emergency which is now more likely to happen because the diver is unfocused.

To be safe, plan for the worst case scenario – a delayed exit that is already stressful. Don't plan to increase that stress by being cold. Be sure that your thermal protection will keep you warm and functional for at least 1.5 times the planned length of the dive (as long as that extra third will last you).

Don't hesitate to add layers if you are using a wetsuit, or to use a thicker undergarment for your drysuit. Extremely cold waters may even require that you use an electrical heating system. Don't worry, it's very unlikely that you will be hot underwater after a long dive. And remember, standing the cold is not a sign of toughness or bravery, it's wasted energy and less fun.

Food and Hydration on Long Dives

Your body will use more energy cave diving than it will on a normal ocean dive; swimming and fighting the cold underwater, and even carrying tanks and equipment to the dive site can be exhausting. You'll need even more energy for a stage cave dive.

Give your body the fuel it needs.

To avoid dehydration and potential cramps, be sure to drink plenty of water; in general and also within 24 hours before your dive. Downing two liters of water immediately before the dive is not enough to get your body to a proper state of hydration.

Equally important is proper nutrition. Feeling hungry from lack of food is probably the least of your worries on a long dive. More dangerous and more distracting are extreme coldness because your body doesn't have the energy to keep you warm; lack of focus (imagining that meal that awaits you after the dive); and hypoglycemia. These can endanger both your and your buddies.

On very long dives, you may find yourself hungry or thirsty underwater despite your best intentions and careful preparations. On these types of dives, pack some electrolyte fluids, candy bars, or even our favorite: plastic baggies of peanut butter so that you can have a snack underwater.  

The Take Home Message About Stage Cave Diving

 Stage diving is a tool to take your cave dives to areas that few people have really seen. However, to be safe and efficient in stage cave diving, it's essential to have your cave diving basics (not only skills, but ability to easily recall long and complex dives) completely solid before even taking a stage course. Once you have the skills and gear for stage diving mastered, remember to take care of your most important asset in cave diving: yourself!

Vincent Rouquette-Cathala and Natalie Gibb are cave and technical diving instructors at Under the Jungle, in Mexico.