Deco in caves

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Sure.

If I am an Intro to Cave certified diver - able to do dives in caves on the main line (no jumps, etc) - and I'm a student in a full cave class, a cave instructor could take me to 130' in a cave and we could stay there long enough to incur significant deco, and there is no standards violation involved.

I guess that is the part that just seems wrong. Taking a diver that is not certified for deco and has no training for deco (i.e. they're not doing that as part of a DP class) on a dive where they incur deco seems like it would be a standards violation with ANY agency. Weird.

In that scenario, I assume the student does their deco on back gas? And how do they know their ascent profile? Are they just expected to fly their computer? They're screwed if their computer dies?
 
they plan the dives accordingly, there is some deco discussions in the full cave course, but stems around backgas deco in theory. This is a very very touchy subject and caused a lot of turmoil this year in particular. The agencies are evaluating a lot of things right now to figure out what they're going to do going forward.
 
I guess that is the part that just seems wrong. Taking a diver that is not certified for deco and has no training for deco (i.e. they're not doing that as part of a DP class) on a dive where they incur deco seems like it would be a standards violation with ANY agency. Weird.

In that scenario, I assume the student does their deco on back gas? And how do they know their ascent profile? Are they just expected to fly their computer? They're screwed if their computer dies?

It depends on the instructor, but in my full cave class deco with O2 was the norm. At a minimum, the cave relevant skills that must be taught are proper placement of the bottle on the line in the cavern and switching to O2 on exit.

Gas switch protocols need to be covered, but with a limited number of dives to cover the requisite Cave skills as well as decompressions skills, students don't have the time or the bandwidth to focus on meaningful levels of decompression training - not to the same extent they would have in an AN/DP class where it is the primary focus of the class.

The same thing applies to the nuances of high percentage O2 use. That's made even more critical when you look at the use of nitrox on long cave dives, where you'll also be using high percentage O2 decompression mixes - 100% O2 is the norm in N FL, but it's not always the optimum choice, and it's vital that things like oxygen toxicity and back gas breaks are covered.

If you polled a number of cave divers Cave certified through agencies that don't offer AN/DP and who never had AN/DP training, I suspect most of them were not exposed to the planning implications of a long dive with a high PP02 bottom mix, and extended deco on O2, particularly on a repetitive deco dive.

Part of the reason for omitting that in training may be an artifact of the Cave training standards being applicable to places other than just N FL. In N FL caves are deep and deco on a long dive at the full cave level is the norm. However in other places, the caves used for training may be shallower and deco may never be encountered. I suspect that's why deco isn't addressed in detail in the Cave course requirements.

But that doesn't eliminate the need for proper deco theory to be taught for divers who are learning and diving in those environments, along with lost deco gas contingency planning, and maintaining enough reserve to enable you to do the much longer back gas deco that may be required.

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Trimix poses the same challenge to a Cave diver as the planning and techniques you'd use offshore don't fully translate to trimix planning or diving in caves. But fortunately for divers at the full cave level, so one seems to get upset when a Cave instructor takes a Cave certified student below 130' on a training dive, because the END should still not exceed 130'.

But given that all the important bottle and gas switching skills are learned in AN/DP and only reviewed and refined in Trimix, it's important for the trimix student to have that AN/DP level of training somewhere, and it's preferable for a cave diver if they can get in a cave.
 
Part of the reason for omitting that in training may be an artifact of the Cave training standards being applicable to places other than just N FL. In N FL caves are deep and deco on a long dive at the full cave level is the norm. However in other places, the caves used for training may be shallower and deco may never be encountered. I suspect that's why deco isn't addressed in detail in the Cave course requirements.

But that doesn't eliminate the need for proper deco theory to be taught for divers who are learning and diving in those environments.

I will be cave diving in Florida in January with a friend who did some recreational level training with me several years ago. He got his final cave training in Mexico, and he had no decompression training then. We completed a week of diving in Mexico a month ago and never came close to exceeding NDLs. Florida will be different. Before we dive, he will be taking some tech training with me in the open water so that we can do the deco that will be required on the dives.
 
This has been a good discussion one that I have enjoyed.
I had never really thought it through why would a Full / Cave diver not really have any deco training.
I see now that it could happen and does.
My instructors required AN /Deco before you could pass Full / Cave.

It would horrify me to know my dive buddy had no deco experience cave diving.
Even with training as previously discussed there are specific challenges planning cave dives.
I applaud the agencies attempting to correct any standards and feel it is in all of our best interests.

CamG
 
This has been a good discussion one that I have enjoyed.
I had never really thought it through why would a Full / Cave diver not really have any deco training.
I see now that it could happen and does.
My instructors required AN /Deco before you could pass Full / Cave.

It would horrify me to know my dive buddy had no deco experience cave diving.
Even with training as previously discussed there are specific challenges planning cave dives.
I applaud the agencies attempting to correct any standards and feel it is in all of our best interests.

CamG

I was ART certified when I did my first full cave course. My buddy had just aow. We both passed. But yes I prefer divers who have already deco experience. But in standards is written that it is not required. As instructor you can say yes or no to a student.
 
...a friend ... got his final cave training in Mexico, and he had no decompression training then. We completed a week of diving in Mexico a month ago and never came close to exceeding NDLs...
I did my cave training in MX as well. Deco was discussed and planned on three different dives. Mayan Blue is 80ish' and getting a deco obligation there is very possible, especially since far fewer places offered Nitrox then than now.
I was AN/DP & TX cert'd prior to cave training, so deco theory was quickly glanced over as I hadn't done more than a handful of dives in a couple of years that didn't require deco. However the planning due to an actual vs virtual overhead was discussed in pretty good detail. That is possibly because of my previous deco knowledge allowing me to form questions that a non deco trained diver wouldn't know to ask.
For the record, my training was done with Protec. If you're going to do your training in MX and plan to, or may consider cave dive elsewhere after completion, make sure you discuss this when interviewing potential instructors/shops.
 
https://www.shearwater.com/products/perdix-ai/
http://cavediveflorida.com/Rum_House.htm

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