Accidental Deco

[Dirty-Dog]

I think I agree. In taking the Deep course you experience rapid gas use, perhaps noticable narcosis, pony use, emergency air hung at 15', etc. What other info. that you'd learn in a tech. course would help the rec. DM? I would imagine one thing is you would get experience in more advanced gas planning which may be of help. What other things?

Other than the things you mentioned, there would also be training in what to do when someone manages to drift over into deco. I'm normally a big proponent of the idea that a diver should be wholly responsible for themselves. But my comments on the subject of tech training were aimed more at a teaching situation - a situation in which it is obvious that the student WILL be diving in conditions and circumstances that are new to them.

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[TMHeimer]

Other than the things you mentioned, there would also be training in what to do when someone manages to drift over into deco. I'm normally a big proponent of the idea that a diver should be wholly responsible for themselves. But my comments on the subject of tech training were aimed more at a teaching situation - a situation in which it is obvious that the student WILL be diving in conditions and circumstances that are new to them.

Gotcha. I assume such things as hanging and using stage bottles would be one thing--As opposed to safety stops of 8 or 15 mins. (or however long gas lasts) if you exceed NDL.

 

[boulderjohn]

Gotcha. I assume such things as hanging and using stage bottles would be one thing--As opposed to safety stops of 8 or 15 mins. (or however long gas lasts) if you exceed NDL.

There is more to it than that. The new OW instruction includes using computers to guide you in an ascent following an accidental violation of no deco limits. That is a much more likely scenario.

 

[oly5050user]

Gotcha. I assume such things as hanging and using stage bottles would be one thing--

As opposed to safety stops

of 8 or 15 mins. (or however long gas lasts) if you exceed NDL.

If you exceed NDL time your stop at 15 ' is NOT a safety stop ..It is a decompression stop ..NDL exceed by no more than 5 minutes, a stop of 8 minutes at 15 ' is required, no diving for 6 hours..Exceed NDL time by MORE than 5 minutes a stop at 15' for no LESS than 15 minutes (longer if air remaining) and no diving for 24 hours..

 

[boulderjohn]

If you exceed NDL time your stop at 15 ' is NOT a safety stop ..It is a decompression stop ..NDL exceed by no more than 5 minutes, a stop of 8 minutes at 15 ' is required, no diving for 6 hours..Exceed NDL time by MORE than 5 minutes a stop at 15' for no LESS than 15 minutes (longer if air remaining) and no diving for 24 hours..

But those rules are only in effect if you are using the PADI RDP for dive planning. The PADI RDP does not have the ability to deal with decompression, emergency or otherwise. Thus, if you are slightly over the NDLs, the rule gets you off the table based on the theory that the 60 minute compartment is still controlling the surface interval. That is why the table "washes out" in 6 hours--6 repetitions of the controlling compartment's half time clears you, and you can start over.

The longer required surface interval is designed on the belief that another compartment that is now controlling the surface interval, and the 24 hour rule is designed to cover all the possible bases.

If you are using a different system to plan your dives, whether it is a table that includes decompression or a computer, then you would not follow those rules and would follow whatever the system you are using tells you to do.

 

[TMHeimer]

If you exceed NDL time your stop at 15 ' is NOT a safety stop ..It is a decompression stop ..NDL exceed by no more than 5 minutes, a stop of 8 minutes at 15 ' is required, no diving for 6 hours..Exceed NDL time by MORE than 5 minutes a stop at 15' for no LESS than 15 minutes (longer if air remaining) and no diving for 24 hours..

My bad. I knew all that, just used the wrong term.

 

[oly5050user]

But those rules are only in effect if you are using the PADI RDP for dive planning.

The PADI RDP does not have the ability to deal with decompression, emergency or otherwise.

THEIMER was refering to RDP..Sure the RDP deals with emergency decompression..Look on the back of it and its right there. Its not designed to PLAN for decompression diving..

Thus, if you are slightly over the NDLs, the rule gets you off the table based on the theory that the 60 minute compartment is still controlling the surface interval. That is why the table "washes out" in 6 hours--6 repetitions of the controlling compartment's half time clears you, and you can start over.

The longer required surface interval is designed on the belief that another compartment that is now controlling the surface interval, and the 24 hour rule is designed to cover all the possible bases.

If you are using a different system to plan your dives, whether it is a table that includes decompression or a computer, then you would not follow those rules and would follow whatever the system you are using tells you to do.

All true''

 

[boulderjohn]

But those rules are only in effect if you are using the PADI RDP for dive planning.
'

I guess that's what I really meant. If you go into deco with the RDP, you can no longer use the RDP for any planning until you have cleared to the degree that you can start over from scratch.

 

[tamas970]

My el-cheapo Subgear XP10 (cheapest computer I could find) can calculate for deco stops. If someone dives 30+m/100+Ft deep, get a dive computer and get familiar with deco procedures. E.g. calculate, how much more air is needed in case of a 10min NDL overdue at 40m/133Ft. Some research on reasonable reserves/nitrox pony can enhance your safety a lot while deep-diving within rec. limits. (Anyway, NDL is not hard science, even if observed, additional safety never harms.)

 

[chrpai]

My el-cheapo Subgear XP10 (cheapest computer I could find) can calculate for deco stops. If someone dives 30+m/100+Ft deep, get a dive computer and get familiar with deco procedures. E.g. calculate, how much more air is needed in case of a 10min NDL overdue at 40m/133Ft. Some research on reasonable reserves/nitrox pony can enhance your safety a lot while deep-diving within rec. limits. (Anyway, NDL is not hard science, even if observed, additional safety never harms.)

Every recreational computer I've owned that can calculate "oh s***" stops has no way of planning those stops. So how would you go about calculating how much more air is needed? You might use some dive planning software to get an idea but the computer isn't going to tell you. Right?