PADI Deco.....

[ColinCB]

I've been noticing this more and more, but it seems like PADI's safety stop/deco procedures are a bit weird. Basically a safety stop to 15'-20' for a few minutes, despite the depth. I feel like this isn't enough. Should I be doing safety/deco stops every few feet for 2-3 minutes, then going up another few feet, etc?

READ ON...

 

[mjatkins]

I've been noticing this more and more, but it seems like PADI's deco procedures are a bit crazy. Basically a safety stop to 15'-20' for a few minutes, despite the depth. I feel like this isn't enough. Should I be doing deco stops every few feet for 2-3 minutes, then going up another few feet, etc?

Just for clarification, are you talking about the emergency decompression instructions taught in the Open Water course. i.e. If you overstay and NDL by less than 5 minutes, ascend to 15 feet and complete an 8 minute deco stop. Stay out of the water for at least 6 hours (the limit on the RDP surface interval credit table). If you overstay an NDL by more than 5 minutes, ascend to 15 feet and complete a deco stop of not less than 15 minutes, then remain out of the water for at least 24 hours.

There is a big difference between a safety stop which adds an extra margin of safety, and a decompression stop which is required in order to avoid an unacceptable risk of decompression sickness.

 

[mjatkins]

I believe you were talking about the recommended safety stops. These are simply performed to add an extra margin of conservatism to an already safe situation. PADI teaches that recreational divers should not be putting themselves in a position where they need to do deco stops. They consider deco diving to be out of the realm of recreational diving, it is technical diving.

That having been said, doing repetitive stops at depth will add to the nitrogen loading that we are trying to limit, and doing repetitive stops near the surface would be unnecessary and ineffective.

I hope that helps. Please don't hesitate to ask any follow up questions. It can be hard to be eloquent over the computer, but I will do all I can to help answer your questions.

 

[ColinCB]

Just for clarification, are you talking about the emergency decompression instructions taught in the Open Water course. i.e. If you overstay and NDL by less than 5 minutes, ascend to 15 feet and complete an 8 minute deco stop. Stay out of the water for at least 6 hours (the limit on the RDP surface interval credit table). If you overstay an NDL by more than 5 minutes, ascend to 15 feet and complete a deco stop of not less than 15 minutes, then remain out of the water for at least 24 hours.

There is a big difference between a safety stop which adds an extra margin of safety, and a decompression stop which is required in order to avoid an unacceptable risk of decompression sickness.

I apologize, I mean deco that's not needed according to PADI. This "deco" would be totally normal, not an emergency during an ascent. Basically deep stops in addition to the "safety stop."

 

[mjatkins]

One more thought, you may be interested in doing a search on the merits of doing deep stops.

 

[ColinCB]

I believe you were talking about the recommended safety stops. These are simply performed to add an extra margin of conservatism to an already safe situation. PADI teaches that recreational divers should not be putting themselves in a position where they need to do deco stops. They consider deco diving to be out of the realm of recreational diving, it is technical diving.

That having been said, doing repetitive stops at depth will add to the nitrogen loading that we are trying to limit, and doing repetitive stops near the surface would be unnecessary and ineffective.

I hope that helps. Please don't hesitate to ask any follow up questions. It can be hard to be eloquent over the computer, but I will do all I can to help answer your questions.

Basically you're saying that under normal conditions deep-stops in rec diving are completely unnecessary?

 

[Diver0001]

Should I be doing deco stops every few feet for 2-3 minutes, then going up another few feet, etc?

The questions in my mind, with all due respect, are what, exactly, do you think you should be doing.... and why?

Maybe I'm wrong and I'm sorry if this sounds sharp, but maybe it's a good idea to get the cart behind the horse and start with defining what it is you want to accomplish.

R..

 

[Web Monkey]

I apologize, I mean deco that's not needed according to PADI. This "deco" would be totally normal, not an emergency during an ascent. Basically deep stops in addition to the "safety stop."

I'm not sure what you're actually asking here.

If it's a non-decompression dive (something that's within the no-deco table limits), there are no decompression obligations and a direct ascent to the surface, without stops, at the recommend rate should be reasonably safe.

The "safety stop" is there for an extra margin of safety and is optional.

Some people feel that deep stops are good, but on a no-deco dive, they're also optional.

Once you exceed the no-deco table limits, you now have mandatory decompression stop(s) to make. These can not be ignored without incurring additional risks of DCS. PADI has a procedure they recommend as do the other agencies, however these are not specific decompression plans, but are emergency procedures that will hopefully prevent you from getting bent.

Terry

 

[ColinCB]

The questions in my mind, with all due respect, are what, exactly, do you think you should be doing.... and why?

Maybe I'm wrong and I'm sorry if this sounds sharp, but maybe it's a good idea to get the cart behind the horse and start with defining what it is you want to accomplish.

R..

You're not being that harsh really, I know what you mean. I basically concerned with eliminating as much gas as possible so there will be little to no risk of DCI after the completion of the dive or subsequent dives. I've been reading about the use of half stops/deep stops for a few minutes as a safety precaution and I was wondering whether or not it had any merit within rec diving.

 

[Bubbletrubble]

You're not being that harsh really, I know what you mean. I basically concerned with eliminating as much gas as possible so there will be little to no risk of DCI after the completion of the dive or subsequent dives. I've been reading about the use of half stops/deep stops for a few minutes as a safety precaution and I was wondering whether or not it had any merit within rec diving.

Have you read the journal articles on the subject of deep stops?

Do a search on the Rubicon Research Repository.

If you're using DCI as an endpoint measure, you should realize that following the "PADI" table guidelines for recreational diving will result in a very, very, very low incidence of DCI. However, you will never be able to eliminate DCI risk altogether.

FWIW, a recent issue of DAN's magazine "Alert Diver" explored the topic of deep stops in recreational diving. Most of the experts thought that deep stops would provide negligible (if any) benefit to the typical recreational diver. The lone dissenting opinion was Peter Bennett who thought that there was enough evidence in venous gas emboli (VGE) studies to recommend doing deep stops. (He was a senior co-author on a couple of the VGE studies, so he probably didn't have the most unbiased opinion.) You should know, though, that a causal relationship between VGE and incidence of DCI has yet to be established. It is thought that an increase in post-dive VGE might be associated with subclinical DCS (fatigue, lethargy, somnolence, etc.)