A Letter to a CyberFriend About To Embark On Cave Diving Training

If you are cavern trained, and are thinking about progressing on to some cave diving classes, you may find some of this interesting.

NOTE: For those experienced cave divers reading this (why are you bothering?), don't cringe too much at some of this... I wrote it when I only had about 12 months of experience... I know better, now, about some of this...

(This letter was written as an answer to many of Michael's questions. Often, I would include part of his question [which start with ">>"] to make the answers a bit easier to understand.)

Michael -

Glad to help, but for every 100 cave divers, you'll get 150 opinions (a lot of them change their minds in mid-sentence ).

It sounds like physically and mentally, you're in shape. I wasn't in very good shape physically, but still made it, so that part will be a breeze for you.

>> I've heard that Lamar is humorless, but he also has an excellent
>> reputation as an instructor.

Absolutely true, he is very good. And he's not humorless... it's just that he has to deal with all those dumb intro-to-cave students!

>> Can you tell me why a swift dump is important when exiting a cave?

The high flow caves will want to PUSH you out... in certain caves like Devil's Ear, out means UP, so you either have to grab on to some piece of limestone and keep pressing the purge valve until you're "flat", or have a fast purge. The purge on my drysuit is slow, so I've learned (the hard way) to think ahead, find a place where I won't be in the flow and out of everybody else's way, and dump a lot of the air out of my wings, purge as much air from my drysuit, then brace myself for a swift exit. It's fun! Now, THAT is a lot of sudden task loading. Even when you're prepared and experienced, it's still a lot.

>> Transpac/metal backplate/wing size, etc. hmmmmm. Cost is about $ 500.
>> I like your idea about used stuff, (for now, anyway). I might just
>> decide to rent for now and wait until I have some experience.

Renting is good, too, especially if you're not going to dive very often. The Divers Supply price for a backplate/harness/pouch/z-knife combo is about $350 or so. Prices from the NACD and NSS-CDS BBS's are even less. (I picked up my spare kit for about $150.)

>> Again, understand that most cave divers use ScubaPro or Poseiden.

Some use the US Divers Conshelf, the Mares Abyss, Dacor Extreme, and some even use the Beachat VX-10. So, although Poseiden and SP seem to be your only choices, they aren't really. The theory, though, goes like this: if several minor things have gone wrong in a cave, that tends to make even more things go wrong; the more things that go wrong, the more likely the diver will start to stress out; everyone has that point-of-no-return where the stresses cannot be resolved; if you have anything but a really good breathing regulator, you may "add" to the stresses by deciding that you can't breathe, that something is wrong with the regulator. There are documented cases of cave divers spitting out a perfectly good reg, with tons of air in the tank: asked later, they state that they couldn't get any air out of the reg. That sort of situation is not physical, it's psychological. That's why I made my statement about, having a good reg is one less thing to worry about.

>> I am intrigued with the new Poseiden Trident...

Sorry, no. It's a Poseiden, but it's not up to the rigors of cave diving. If you purchase Poseiden, get either then Odin or Cyklon 5000.

>> I am now thinking of waiting on many (all) of these purchases until I
>> get to FL and get to talk to other divers and the folks you mentioned
>> at Ginnie.

Boy, then you'll be REALLY confused!

>> Would you have a phone number for Ralph Hood?

Ralph Hood 804-872-8741
  Underwater Connection Inc.
  171 Cornell Drive
  Newport News, VA 23602

>> Think DR manifold use slip in O-ring quick connects rather than screw
>> threads. I think.

I'll admit that I'm no expert on any manifold except the one I own, and I KNOW it's got limitations! However, I did order and install the H-valve from DiveRite (which is about 1/3 of what I'd need for a complete manifold), and I like it.

>> I've arranged to rent double 104's from Wings with manifolds.
>> ($15/day).

Good choice. I'd love to be there the first time you have to walk to the spring! . My first time, I thought someone had accidentally put a dump truck on my back. UUUGGGGHHH

>> Good advice; might just stick with my Datamax Sport for now, until I
>> decide. Do you go with only one computer? Back up depth meter and
>> timer??? Or another backup computer?

Like you, I already had a dive computer when I decided to cave dive, but unlike you, it was an Aladin Pro. Does the Datamax Sport provide for deco stops? You'd better check. If not, then you'll have to use tables, and THAT will leave you in the water for quite a while (use DCIEM tables if you can get them).

Although I don't have a back-up computer, I do have a Citizen Hyper- Aqualand, which records depth and bottom time (and provides for some neat downloaded profiles, later). With the HyperAqualand and the tables in my pouch, I can get out of the water bend-less if my computer does go haywire.

>> Good point. Tho I don't have a regular CD partner......I'll have to
>> decide on my own. And decided I'll have to deal with that later;
>> can't very well bring them back on a plane!

Yeah... I read Robbie Osman's message to you about not buying any tanks at all, and doing your diving in Akumal. Pretty good advice; but you might ALSO want to start a Christmas account and save up for some nice 104s. I use my 104s for deep diving, too, so they can come in handy for more than just the occasional Florida trip. And, I've heard about some u/w caves in the Idaho, Wyoming, Utah area... could be, with your skills (rock climbing, dry caving, etc.), you could have some major finds if you go poking around! Then, of course, you'd need the tanks!

>> Not so much my legs; rather those three slowly degenerating lumbar
>> vertebrae! When I pull them into disarray, it sets me back for
>> months. NO FUN.

Okay, dude, here's my secret. If you tell anyone, I'll have to kill you. In 1977, I had back surgery: herniated disk. Like you, carring around heavy weights is mucho terrible'. But here's the GOOD part: since I started cave diving, my back has gotten BETTER! It's not documentated, but I have lots of anecdotal evidence that every dive is like a hyper- baric O2 treatment, especially if you use pure O2 on the 20 and 10 foot stops. These "treatments" have cured lots of ills, as told to me by many, many different cave divers around the world. So, IMO, the short hike to the springs with 125# of cave kit WILL be compensated for by your 60 minutes of higher PPO2, and maybe then some. And, of course, nitrox dives are even better than air.

>> Got it; is Diver's Supply at Ginnie?

There are several towns that have a Divers Supply, but the closest to Ginnie is in Gainesville (a 25 minute drive). However, you should call them (800-999-3483) and have them send you a detailed catalog, so you can start dreaming and salivating. I meant to mention before that you should dedicate 1 entire day toward acquiring gear. For me, my 9 days was 9 FULL days, and I didn't have time to go get anything.

>> (Another hint: dial up the NACD and NSS-CDS bulletin boards. There
>> are usually people selling stuff that you'll want and need.)
>> Gotcha. Don't have those numbers at fingertip, do you?

NACD BBS: 912-246-3280

NSS-CDS BBS: 813-648-9400

>> Wow again; never thought of scooters as dangerous!!! Thought they
>> would be a real blessing. Damn, I've sure got a lot to learn.

I got the Peacock rangers mad at me for doing a scooter dive "too soon." They'd like to see 100 dives or more before anyone does a scooter dive. But, I knew Peacock really well, felt comfortable on the scooter, and knew I could swim out at any time with no problems, so I did it. It was fun. I would have preferred more experience, but I didn't have any problems and ya gotta start somewhere!

>> "cave divers often relocate, changing jobs and domiciles, in order to
>> live near the sites ..."

I think about it.... A LOT!

FWIW, the two most common problems cave diving students have during their "9 days" (based on my own experiences, and experiences shared by others) are:


  1) buoyancy
  2) line awareness

1: your kit will be A LOT heavier than you're used to, and changes happen much slower. You'll need more air in the wings than you're used to putting in your b.c.. You can be going through a tunnel that you think is level, but it's slowly descending, so before you know it, you're negative. And, of course, the opposite is true. The one TRUE test is, stop swimming, stop moving, and see what happens. About 59% will start rising, 39% will sink, and 2% will stay where they are. Constantly adjust your trim, but don't worry about it for the first few days (you'll have LOTS to do).

2: Line awareness is much more than simply watching the line, or "knowing" that it's "over there, somewhere." The problems occur when you're tooling along, thinking that everything is hunky dory, you're right OVER the line so you can't possible mess up, and you really are starting to enjoy the dive rather than see it as a series of tasks to deal with... then, something distracts you for a second, you waver, look for the line, find it and start following it again. Trouble is, it's the WRONG line! You don't even know to ask yourself "am I sure this is the right line" because you NEVER SAW what happened. This scenario happens more frequently than you'd imagine, and has killed divers. It happens when you haven't looked at the line in a while, get distracted for a moment, and/or waver away from the line for a moment, look down or around and see an *off-shoot* line and don't question that that is INDEED the correct line, and follow it dutifully off into the cave.

Problem #1 has happened to me twice during my training, and only gets better if you dive a lot. The first time, my instructor when off somewhere to do something and I was waiting, and it wasn't long before I found myself near the ceiling of a large domed room. When he came back, I tried to look nonchalant, like "hey, I *meant* to do that", but John knew better and laughed. (Yes, instructors know how to laugh underwater... irritating bastards! ) The second time, I was again waiting, and was only inches from a very silty floor, when I just suddently sunk. I stuck my hand out and it sunk about 4-5 inches into the muck. With my free hand, I put a little air in my wings, then VERY, VERY slowly pulled my hand out. Later, John admonished me for losing my neutral buoyancy, but applauded the fact that I kept my wits about me and didn't stir up the silt.

Problem #2 I've done twice, once during training, and once on a dive not too long ago. During training, I was hovering at the jump between the Peanut line and the Crossover tunnel in Peacock, waiting for John to retrieve the jump reel, and I got distracted... I looked up, saw the line and started swimming. After about 5 kickcycles, I stopped and realized that this was "not right". Almost immediately, I saw John's light flashing and turned around sheepishly... I was heading futher down the Peanut line. After that, he told me he watched me go and wanted to see how far I'd get before I noticed. It was a good lesson, and I passed! The other time was on a dive with 2 other fellows, and I was swimming, but looking behind me, looked up, saw the line and followed it. It was an off-shoot... Again, I noticed almost immediately that it was wrong, but the other guys bragged later than they had to "go get me"... wrong, but I let them brag...

Both #1 and #2 occurred during my training because I got distracted, and the main thing that distracts you during training is your kit. You look down, your eyes focus on something inches away, so you loose your peripheral vision of the cave, and loose any reference points that will tell you if you're sinking or rising, loose track of the concept of "where you've been" and "where you're going" so running off in a different direction is possible. So, this emphasises how important familiarity with your kit is... if it distracts you, then in essence, that's just one more task to deal with that can quickly add more tasks.

By the way, I've since learned that the sense of "where you've been" and "where you're going" differs with each individual. Some divers can go into a cave once and "know" it (although this is pretty rare, and virtually impossbile during training since you're paying attention to so many other things). Others take 2 or 3 dives in the same cave before it seems familiar (this is me). Yet others seem to never catch on to cave landmarks and layout (you don't want to dive with these types leading!). So, during your training, you may find that you've finished your dive and don't have a CLUE what the cave looked like. This is not unusual, but you can be sure the instructor won't miss the opportunity to slam you for it.

One of the big thrills for me now, is to go into a cave that I've been in twice before and feel that first-time sense of "knowing" what the cave is like. Really a neat feeling. Some day when you've got 45 minutes, I'll tell you about my Waterhole dive.

Well, I guess I should get back to work! Feel free to ask more questions, if you have them.

                                    - Robert

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