Why scooter cave exploration is safer than what you may think
By Ivo Kalushev, leader of the ATI Cave Exploration Team in Mexico
and owner of the DivingMexico cave diving school (http://divingmexico.com)
DISCLAIMERS: The article below applies mainly to sidemount diving in Mexican setting – i.e. shallow caves. Some points about deep cave exploration have not been touched. Additionally it does not apply in any way or form to recreational scooters, or recreational diving. Finally, this reflects entirely my own view, based on my own experience in very specific circumstances and style of exploration. Other people think, and do, differently. Based on all that, take it for what it’s worth.
I decided to write this piece after one year of daily scooter cave exploration in difficult side mount caves, often pushing the envelope close to the limit of what is advisable. I feel that there are a lot of misconceptions about this topic, and also people are not really aware of the new advances in technology and about what the real exploration scooters are capable of. This is not an endorsement of any particular brand of DPV’s, although I do have my bias, but instead I will write a little about the philosophy of scooter exploration, the underlying dangers and considerations.
From the first day of our cave diving education, if our instructors are good, we are taught to think critically and to be mindful of the vast array of dangers cave diving has to offer. Accident analysis is part of every cave course and we learn to always err on the safe side and make the most conservative decisions which are practical for each particular situation. This over emphasis on danger is somewhat healthy, teaches us discipline and is no doubt needed for those of us who are slow to learn, or who are prone to playing ego games underwater. To a great extent however this is a byproduct of the period when cave diving deaths were common due to lack of knowledge and inadequate equipment. We still have some of this, but on the other hand I have no doubt that this overcautious approach has sometimes contributed to accidents and is often creating additional fear, which is the last thing we want in cave diving. We all need a balanced perspective and real knowledge, not emotion-based reactions to new problems and situations.
The current attitude towards scooter cave diving and especially towards scooter cave exploration is very much a product of all this. It is a complex mix of conditioning, seeking revenue from courses, preserving one’s own elite status and some real safety considerations. Scootering is seen as a very advanced form of cave diving, often multi stage training is required as a prerequisite to a Cave DPV course. Scooter cave exploration is still on a further level, reserved only for very few. In fact here in Mexico apart from our team the only other team which routinely uses scooters for long range exploration on a daily basis is the Zero Gravity team for the Ox Bel Ha project. This is truly seen as the pinnacle of cave exploration diving.
All this is very ironic, because scooter cave diving is much safer than non-scooter cave diving, and on top of that the learning curve for DPV diving is very flat – to the point that there have been many arguments against the need for DPV courses at all. I am not an advocate of removing the DPV courses from the curriculum as there are valuable things to be shown and learned, but we have to be honest about all this.
Why are scooter cave dives safer?
Now, our usual thinking as cave divers is that the more equipment we add, the more intrinsically unsafe our diving becomes. This is stressed so much, especially in the area of sidemount cave diving, that it has become an axiom. We all know the stories of accidents in which complicated equipment has contributed to a fatal outcome. It is all true, but does not really apply to scooters. When someone shows us a scooter and tells us to use it, the task loading warning lamp will light in many of us and we would go “WOW dude, not me, I am a simple cave diver. This thing can kill me.. it can break… it can take me too far, etc”. I had the same attitude when almost two years ago we reached a point in our exploration when we either needed to stop, or continue with scooters. Other cave exploring friends were not of much help, as this attitude was prevailing among all. As we learned later it could not be further from the truth. We decided to get four SUEX expedition units and from then on our diving moved to a new level of safety and quality.
Why is using a scooter in a cave safer? Very simply put because with adequate planning it helps you conserve gas. If you have to go from the entrance (point A) to point B ‘on foot’ and you will reach your thirds at point B, then if you use a scooter you will have exhausted maybe only one fifth of your gas when you get there, and often even less. Even if your scooter breaks at this point, or at any point along the way, you will still have much more gas to do whatever you need to do than what you would have if you were not scootering. Additionally, you will not be tired from the constant kicking. If you know how to plan your dives this thing alone will provide you with a safety margin far greater than what you are used to. If you have more than one good unit with you the chances of you being left without a scooter also virtually disappear, as a good expedition grade DPV has no problem bringing two, or even three people out of the cave with very little penalty in battery scope or speed. However you look at this problem, if you know how to plan your dives every meter done with a scooter in the cave is a plus for you, safety wise. And I have not even said anything about the added comfort.
What are the main dangers in using scooters? Basically if you don’t know how to plan your dive they can take you too far and then die on you, thus leaving you with insufficient gas to get out on your own. If you know what you are doing this will never happen, but I will expand on this point in a moment. A much more real danger is to jump a line unintentionally while momentarily being distracted. As you are moving faster with a scooter it doesn’t take much to do this mistake, and it can prove fatal. Nowadays most cave diving deaths are due to navigational errors, especially here in Mexico, so this should not be taken lightly. This is the only real risk, and we have to learn to pay attention. There are other small things to be mindful of but they can be shown to you by whoever is taking care of your DPV training, and they are not really issues for anyone who has basic knowledge about cave diving.
Scooter dive planning for exploration
Simply put, when you do scooter cave diving you should never plan by gas, but by distance. There are endless discussions about how to plan your DPV cave dives on gas. Some say 1/6, others go as far as 1/16. This is ridiculous, you should never do that. Scooters in caves are most useful when you know where you are going. Gas planning using percentages never really works for scootering, but we will get to that shortly. Basically when you use scooters you already know where you want to go and how much gas you need to exit from there. Based on that you use the scooter to extend your safety margin, to conserve your energy, and to have more gas at your disposal for exploration ‘on foot’ using as a base point the initial point you reached with your scooter (and where you left your scooter). That’s it, that is how a scooter is used in exploration. You don’t just blast off in some unknown direction laying line on thirds praying for your scooter not to die on you. Whoever thinks that this is a good idea, should not be even driving a car, let alone diving, let alone cave diving, let alone DPV diving… So it is really very simple, you use the scooter as a tool, fully knowing what you are doing. And you plan based on distance only. When you get good at this, you start to be able to judge accurately many things, and incidentally among them is a certain feel for gas management. But this is an esoteric aspect of the craft, not something which can be taught. You need hundreds of exploration scooter dives before you hone that skill.
Well, you might ask… “Can’t I get my scooter to a new place for me, to see a cave I have never been to before, but which already has line laid?” – i.e. not exploration related. Of course you can, and we all do it all the time, but you should also be aware that there is no safe way to plan your gas in such a situation. I repeat – there is NO safe way to plan your gas. A 40 minutes swim can be a 10 minute scooter dive on moderate speed. You may dive on 1/8-ths with a DPV but this still may not be enough. Why? Because you will never really be sure. You don’t really know what distance you covered, you don’t really know if you have enough gas to get out. If a situation occurs chances are that you will panic more easily, just because of this uncertainty, even though you may actually have more than enough gas. This is not a situation you want to put yourself in. Most seasoned cave divers should probably do no more than 15 minutes of hard one directional scootering in an unknown cave before considering stages, and this is a very general guideline only and applies for persons with experience and good SAC rate. You are on your own there, and sound judgment is the only thing which can help you live.
What about DPV courses?
DPV courses are very useful, as there are certain safety procedures to be shown and trained. You have to know what to do in the case of a runaway scooter, in case of entanglement, you should know how to ride with a buddy, how to take a spare scooter etc. and also there are some very specific and valuable fine points for exploration and also for use in sidemount caves. As with everything else it is a craft, and it is best learned from someone who has much experience. This will make your life easier and can potentially save you time and even trouble. That being said however, a good experienced cave diver who is completely proficient in the fundamentals and is comfortable in the overhead environment should be able to learn to handle a scooter within a day or two. This is not rocket science and to deny that is to serve the interests of certain diving corporations which should not be encouraged in this respect. I do own a cave diving school and we do offer DPV training, but this is the first thing our students are told at the start of a DPV course. We should not twist the facts, and we can not teach properly while at the same time encouraging someone to suspend judgment about simple obvious things. Scooter diving is quite simple to do for an experienced cave diver.
In this regard, if you want to do high quality DPV cave training in Mexico, apart from our school, I can personally recommend Steve Bogaerts at Go Sidemount (SS Scooters), and Fred and Chris at Zero Gravity Dive Center (GUE/DIR style, SUEX scooters). If you do your training at any of these places you will not be making a mistake.
Which are the best scooters for cave exploration?
Long gone are the days of the constant DPV repairs. Today’s exploration units are both very reliable and long-range. A few scooter manufacturers are currently trying to target the cave diving community, with SUEX, Bonex and Silent Submersion leading the group. All these companies produce reliable scooters, but have made very different design decisions. My personal preference is firmly with SUEX, for many reasons, but those are also expensive units and it is not an easy decision to invest in one. However, with 13+ kilometers of range and amazing reliability, they leave really very little to be desired. The XK1 exploration scooters we are equipped with have been used daily for over one year now and to all intents and purposes are still like new. There seem to be some other good brands out there too and this market is in constant development, so one should always stay informed.
The important points with a scooter is foolproof design, durable construction (less plastic is better!), and good choice of high-end battery technology (various types of Li-Ion batteries are the standard now). Exploration specific additions are also very useful, like emergency bypass switches, detachable props, battery level indicators, etc. IMHO things like adjustable prop blades, nylon thread triggers and such have some weaknesses, even to some extent brushless motors (which are the future, but rely entirely on electronics) are questionable in serious cave exploration, but they have proven to work for many. Still when I put my trust in something I want it as simple and robust as possible. No matter what you choose however, it should be tested, and tested, and tested, until you develop trust in the machine. Then you will never want to go diving without it again.
Final thoughts and disclaimers
In short, for scooter cave exploration you have to have the best equipment you can afford, follow some basic common sense rules and never rely on only one scooter in a dive. There are tips and tricks, and some go contrary to normal cave diving logic, like going as fast as possible on the way in (when you know where you are going to) and other fine points, but generally if you know what you are doing and if your head is in the right place you will be safer using a scooter than exploring without one. You will be less tired, you will have more of your attention for other things, and more importantly you can have more gas to do what you really came for inside the cave instead of wasting it only en route. And… did I mention anything about fun? Scooter diving is GREAT FUN! :))
Hope this helps someone. I wish you all safe diving. We should never stop learning and we should always share our knowledge.