Deep stop

[sdiver68]

In DAN's Alert Diver magazine a few months ago there was a debate about the deep stop. In the end, I think the advice given was if your computer says to do it then do it, if not don't worry about it. Now that I think about it that's a good way to gather more statistics if I were DAN, lol.

But anyway, that's not my question. My new dive computer Oceanic VT4 has a deep stop on/off option in the set-up menu. Now what?

 

[deepstops]

In DAN's Alert Diver magazine a few months ago there was a debate about the deep stop. In the end, I think the advice given was if your computer says to do it then do it, if not don't worry about it. Now that I think about it that's a good way to gather more statistics if I were DAN, lol.

But anyway, that's not my question. My new dive computer Oceanic VT4 has a deep stop on/off option in the set-up menu. Now what?

I can only provide my personal observations and they would be that the first five years I was diving, I dove "normally" using 30'/minute ascent rates and 3 minute safety stops. While I enjoyed diving greatly, I typically felt quite tired in the afternoon after the typical two dive morning. Essentially this is sub clinical DCS.

In 1998 I heard about doing a two minute half max depth stop followed by a slower ascent from there to the safety stop and tried it out. I felt so much better after my dives it quickly became "how I dive".

 

[scubadada]

I can only provide my personal observations and they would be that the first five years I was diving, I dove "normally" using 30'/minute ascent rates and 3 minute safety stops. While I enjoyed diving greatly, I typically felt quite tired in the afternoon after the typical two dive morning. Essentially this is sub clinical DCS.

In 1998 I heard about doing a two minute half max depth stop followed by a slower ascent from there to the safety stop and tried it out. I felt so much better after my dives it quickly became "how I dive".

Hi Brian,

Interesting anecdote. Diving essentially within recreational limiits, I did the same n=1 experiment and found no difference between making a deep stop or not. I did not add a deep stop to my routine though I know others that have. The utility of deep stops may be different in technical diving.

I found reading the 2008 Decompression and the Deep Stop Workshop Proceedings, Undersea and Hyperbaric Medical Society, most enlightening with regard to the available evidence. To each their own.

Best, Craig

 

[lowviz]

Hi Brian,

Interesting anecdote. Diving essentially within recreational limiits, I did the same n=1 experiment and found no difference between making a deep stop or not. ...//...

I did. -found that over the years the big deal is that it just slows me down on my rush to get back on deck.

 

[PfcAJ]

The trick is to not make the deep stop too long. Defining "too long" is tough.

 

[Bubbletrubble]

The trick is to not make the deep stop too long. Defining "too long" is tough.

Most computers on the market that can be set for a "deep stop" specify a duration of one minute.

For a given profile, it's unknown what the optimal depth, duration, and number of deep stops are.
FWIW, there have only been a handful of studies that have tried to judge the "quality" of various ascent profiles by Doppler-detected venous gas emboli.

@sdiver68: For recreational dive profiles, not enough research has been done to demonstrate that deeps stops provide any benefit at all.

Do the deep stops or don't do them. It's up to you.

Personally, I think that the computers that include the "deep stop" feature are a little gimmicky. Arguably, the feature was incorporated into the software as a marketing move. One can certainly perform deep stops with a computer that lacks such a feature (although the computer won't decrease the duration of the recommended safety stop).

For the dives that I've done in the 80-120 fsw range, I haven't observed any difference whether I include deep stops in my ascent profile or not. I always do a 5-7 minute safety stop with a slow (2 minute) final ascent to the surface. YMMV.

 

[lowviz]

...//...Personally, I think that the computers that include the "deep stop" feature are a little gimmicky. Arguably, the feature was incorporated into the software as a marketing move. ...//...

Don't mind me, just preserving this quote for posterity.

 

[kdsmithjr]

I would turn it on....it might not help, but it won't hurt anything. I am certain that the programmers of the dive comp set everything up to invoke a deep stop if it is adviseable.

 

[lowviz]

I would turn it on....it might not help, but it won't hurt anything. I am certain that the programmers of the dive comp set everything up to invoke a deep stop if it is adviseable.

Please do turn it on. Only takes a minute...

 

[Jax]

In DAN's Alert Diver magazine a few months ago there was a debate about the deep stop. In the end, I think the advice given was if your computer says to do it then do it, if not don't worry about it. Now that I think about it that's a good way to gather more statistics if I were DAN, lol.

But anyway, that's not my question. My new dive computer Oceanic VT4 has a deep stop on/off option in the set-up menu. Now what?

I can only provide my personal observations and they would be that the first five years I was diving, I dove "normally" using 30'/minute ascent rates and 3 minute safety stops. While I enjoyed diving greatly, I typically felt quite tired in the afternoon after the typical two dive morning. Essentially this is sub clinical DCS.

In 1998 I heard about doing a two minute half max depth stop followed by a slower ascent from there to the safety stop and tried it out. I felt so much better after my dives it quickly became "how I dive".

sdiver, I had exactly the same issues as Deepstops. At that time, I was 100% recreational. I was so tired in the afternoons, I began to think diving was not for me. I read the book by Mark Powell, "Deco For Divers". In the book, Pyle noticed that he was not nearly as fatigued on some dives as others. He kept records, and noticed that when he stopped to release the gas bladders of his fish (about two minutes), he felt way better.

I incorporate the deep stops - two minutes at 1/2 of my max depth. Now my computer chooses that Position Dependent Intermediate Stop (PDIS) and it works for me.

The question is, do you know yourself well enough to know the difference? Turn it on and give it a try.