decompression without training

[Doc Intrepid]

If your dive takes you into deco by "accident" either your dive plan was bad or you did not follow your dive plan.

+1

The objective is to learn how to plan your dive and dive your plan.

This is not just a goal for recreational NDL divers - it is the rule for all divers. Technical planned-decompression dives require more planning and adherence to time and depth, not less.

So as you are learning to dive, plan and execute your dives to ensure your new computer never goes into deco. Certainly you can conduct a slow ascent on a recreational NDL dive and likely respond calmly should it occur (assuming you have sufficient gas, another issue). But the goal is to learn how to dive so that your new computer never "accidentally" goes into deco in the first place.

 

[11kiwidiver]

nothing advanced about AOW I agree

 

[muddiver]

Thanks for the info. I'm still trying to digest it, seems unbelievable to me. What is advanced about AOW? Isn't Nitrox for staying down longer and/or going deeper? No decompression talk there either. OK then thanks again. WOW

The majority of recreational SCUBA diving courses are kept within the No Decompression Limits of the table followed by that particular certification agency. This is one of the tenets of not having to submit to a government agency for regulation of recreational diving. At least here in the U.S.

When you leave the limits of the reccognized tables you are now in the realm of Technical Diving and you are no longer within the scope of training of the standard recreational SCUBA diving certification. There are a few organizations that do train decompression diving and other specialties like cave and werck penitration diving (i.e. GUE, TDI), but the amount of equipment needed and amount time time required far exceeds any standard certification.

 

[UCFKnightDiver]

The majority of recreational SCUBA diving courses are kept within the No Decompression Limits of the table followed by that particular certification agency. This is one of the tenets of not having to submit to a government agency for regulation of recreational diving. At least here in the U.S.

Perhaps I am misunderstanding you here, but the technical agencies that do teach courses such as decompression don't have to submit to to a government agency for regulation either...

 

[Thalassamania]

The original definition that exempted recreational diving instructors was based on the premise that it was no-decom diving, on air. While some changes have been found acceptable ... the further you stray from that description to closer you are to having one bad accident sweep the entire community back under OSHA.

Incidentally, if you think that, "the technical agencies that teach courses such as decompression don't have to submit ot a government agency for regulation," I suggest that you read this: Regulations (Standards - 29 CFR); Alternative Conditions Under 1910.401(a)(3) for Recreational Diving Instructors and Diving Guides (Mandatory) - 1910 Subpart T App C

 

[MXGratefulDiver]

There is nothing magical about deco ... and keep in mind that computers are nothing more than mathematical representations about what "might" be happening inside your body based on some assumptions about an idealized human being. In other words, your computer knows nothing about your body, or your predispositions toward decompression sickness. For this reason, they build in an inordinate number of safety factors.

That said, if you are going to use your computer to calculate your no deco limits, understand the information it's giving you. If you should go into deco, your computer display will indicate a ceiling that you should not go above until it "clears". It will also tell you how many minutes you must remain below that ceiling. I had the unfortunate experience once to dive with a fellow who thought his computer was telling him to go to that ceiling ... and he therefore went from 120 feet to 10 feet rather in a hurry ...

Don't do that.

If you should go into deco, you should begin ascending immediately. Depending on your depth, you may want to move up at a moderate pace until you've reached about half your original depth. If you have the gas reserves, pause there for about a minute ... this is to be nice to your "faster" body tissues such as your blood and nervous system and let them get rid of some of the excess gas that's trying to get out through your breathing exhalations. Then continue your ascent to either your safety stop or the "ceiling" indicated on your computer ... whichever is the deeper depth. Remain there until your computer says it's OK to surface. Then SURFACE SLOWLY ... taking at least a half-minute to a full minute. Most people tend to shoot right to the surface when their safety stop is over ... that's already a bad practice, and even worse if you've gone beyond your no-deco limits. Monitor your gas supply, of course ... but if you have the gas for it, slower is better.

A couple years ago I wrote this article in response to someone who asked me the exact same question. You may find it useful.

... Bob (Grateful Diver)

 

[UCFKnightDiver]

The original definition that exempted recreational diving instructors was based on the premise that it was no-decom diving, on air. While some changes have been found acceptable ... the further you stray from that description to closer you are to having one bad accident sweep the entire community back under OSHA.

Incidentally, if you think that, "the technical agencies that teach courses such as decompression don't have to submit ot a government agency for regulation," I suggest that you read this: Regulations (Standards - 29 CFR); Alternative Conditions Under 1910.401(a)(3) for Recreational Diving Instructors and Diving Guides (Mandatory) - 1910 Subpart T App C

Interesting, I had never seen this before until now, though to be honest I dont see anything about decompression diving. (no deco diving I do) Also technical agencies teach hypoxic mixes with trimix, it says breathing gas must not contain a lesser percentage of o2 than that of air. (EDIT I see that it says NITROX gas mixtures)

 

[LeadTurn_SD]

..... A couple years ago I wrote this article in response to someone who asked me the exact same question. You may find it useful.

... Bob (Grateful Diver)

Hi scubasteve0011,

The article Bob wrote is aimed directly at questions like the ones you are asking. If you have not already read it, I'd recommend doing so (along with the other fine articles on his website).

This has been a good discussion. Just a couple things I had not seen mentioned (or I missed ):

1.) For most "new" divers using a single Al80 it is very tough to get into deco during a medium-depth multilevel reef dive if it is the 1st dive of the day; but it gets far easier to "stumble" into deco on the 2nd or 3rd dive of the day if you don't pay close attention to your new NDLs.

2.) Most computers have a "planning" mode that scrolls the updated NDLs after your first dive (and subsequent dives). Make it a point to always study the new depth/time limitations before entering the water for the repetitive dive.

Best wishes.

 

[Damselfish]

The question is, why do you want to go into decompression? It's not hard to avoid doing it by accident. And if you can't avoid doing it by accident, then you're not ready to be doing it on purpose. Just because it seems easy to do so with a dive computer, doesn't mean most people are doing it or it's a good idea.

Minor deco obligations may not be a big deal, especially of the sort where ascending a bit will clear the obligation. But that amounts to "pushing" your computer, which isn't the greatest habit either. It's just a slippery slope to start down if you don't understand the basic issues around deco.

 

[MXGratefulDiver]

The question is, why do you want to go into decompression? It's not hard to avoid doing it by accident. And if you can't avoid doing it by accident, then you're not ready to be doing it on purpose. Just because it seems easy to do so with a dive computer, doesn't mean most people are doing it or it's a good idea.

Minor deco obligations may not be a big deal, especially of the sort where ascending a bit will clear the obligation. But that amounts to "pushing" your computer, which isn't the greatest habit either. It's just a slippery slope to start down if you don't understand the basic issues around deco.

No matter how careful you are, everyone eventually makes mistakes. It's far better to know in advance how to get yourself out of a situation than have to figure it out once you're already in it ...

... Bob (Grateful Diver)