Safety stops

[danvolker]

someone wrote

It is my understanding this is, in fact, wrong. Off-gassing is most efficient while doing light (emphasize light) work -- i.e., slowly swimming -- since this encourages increased and efficient blood flow and respiration, not to mention keeping blood flowing to all of your extremities.

BTW, how is a "safety stop" NOT a "deco stop?" Are you not off-gassing during a "safety stop?" If so, are you not decompressing at that time? Also, within the PADI RDP system, when there is a "mandatory safety stop" how can that not be a "mandatory deco stop?"

I agree. When George Irvine began mentoring me in deco shapes and strategies, he had us doing light swimming during deco, and if you had been carrying a speargun ( or a camera), you would need to get the weight off the arms so the muscles could relax ( previously there would have been constrictions from a long period of muscle contraction) and try to get plenty of gentle movement in the arms to help promote blood flow.


If I was trying to explain off-gassing to a new diver--and this IS the forum for this ... I would make sure they understand that a Safety stop IS a Deco Stop....because you are decompressing from the bottom depths you had just been at.... But I would also make it clear that if they have stayed within the tables for this dive, that they CAN swim straight to the surface at a 30 foot per minute ascent rate --if they need to....and in fact, if they had experienced a serious event or emergency situation, they could safely surface at 60 feet per minute without a STOP.
However, a Stop should be planned by the new diver, both for the Ascent speed control redundancy it represents ( Thanks Thal!) AND FOR avoiding being hit by a passing boat overhead. And, the idea of doing a deco stop is not a bad one...it may make the diver more energetic the rest of the day, as opposed to what happens when they are eliminated ( for some divers). It will also have a safety margin it will add to your No Stop table planning for the dive.

 

[Sam Miller III]

All the posters post with great authority but none have answered the question
"When did making a safety stop for a few moments (time varies) become requirement, or a suggested diving protocol?"
Who or what agency first initiated the requirement, or suggested a stop as a diving protocol? And why is the stop so important?
I suspect the 0-24 divers would not have the answer but would appreciate an answer as I would from the divers who have 2500 to 4999 dives, who I just don't log dives, and are a fish...
SDM

 

[flots am]

. . .

 

[chrpai]

And why do you care that I don't log dives?

 

[danvolker]

All the posters post with great authority but none have answered the question
"When did making a safety stop for a few moments (time varies) become requirement, or a suggested diving protocol?"
Who or what agency first initiated the requirement, or suggested a stop as a diving protocol? And why is the stop so important?
I suspect the 0-24 divers would not have the answer but would appreciate an answer as I would from the divers who have 2500 to 4999 dives, who I just don't log dives, and are a fish...
SDM

So this is your first time trying to "herd cats" ?

 

[GrimSleeper]

In answer to the actual question,

When you are one your safety stop can you stay there as long as you want?

The answer is simple: Yes. So long, obviously, as doing so doesn't mean (a) going out of gas, (b) going hypothermic, or (c) really, really annoying everyone else on the boat. You could, in terms of how much overpressure your tissues can withstand without inert gas bubbles forming, spend the rest of your life at 15 feet and come straight to the surface (at a controlled ascent rate).

sam miller, that was the question originally asked. I've no idea what the answer to your question is, and I don't really care. Nor, I'd suspect, does the person who started the thread. I do know I'm quite happy putzing about the reef at 15-20 feet for a while before I surface, so what's the big deal? If it was you who invented the safety stop and you're upset you didn't get the credit, I'll happily do 'sam miller stops' from now on if that makes you happy. I did Pyle stops for long enough, until decompression modelling moved forward and and deep stops started to be accounted for in the underlying models... If, on the other hand, the idea of a pause before surfacing annoys you, don't do it, I'll see you in three or four minutes when I get back on the boat.

As for

In tec diving what we do is do our deco stops while remaining still because if you are more active, it is more difficult for your body to release nitrogen.

The problem with throwing an irrelevant reference to tecnical diving into a question about safety stops in sport diving is that, sometimes, instead of making you look clever it just makes it obvious you (at best) haven't kept up with the literature. As Peter and Dan have both said, light exercise (ie a gentle swimming motion) has long been recommended during stops in order to boost circulation and thus efficiency of off-gassing. And actually, if you read some of the latest literature on the subject, it's being suggested that technical divers should be aiming to work about as hard during the decompression phase as they did during the on-gassing phase, the argument being that working the circulatory system hard and thus on-gassing 'efficiently' should be matched while trying to get the gas back out. Of course, that needs to be balanced against the risks of working hard and generating excess CO2 while breathing high inspired ppO2s. But this really isn't the forum for that discussion, since it's New Divers.

So, back to the OP's quite straightforward and much-hijacked question, just to confirm, within reason, YES - spend as long as you like on your 'sam miller stop'.

 

[buddhasummer]

All the posters post with great authority but none have answered the question
"When did making a safety stop for a few moments (time varies) become requirement, or a suggested diving protocol?"
Who or what agency first initiated the requirement, or suggested a stop as a diving protocol? And why is the stop so important?
I suspect the 0-24 divers would not have the answer but would appreciate an answer as I would from the divers who have 2500 to 4999 dives, who I just don't log dives, and are a fish...
SDM

Unless my comprehension skills have failed me again these were not questions asked by the OP, I believe his/her question has been answered. Sorry I don't know the answer to your questions. If the answers to these questions are important to you perhaps you could start a new thread I'm sure someone would know this info although I suspect you may already know the answers. The answer to your question of "why" I believe has been answered in some detail. Good luck with your search.

 

[brnt999]

Unless my comprehension skills have failed me again these were not questions asked by the OP, I believe his/her question has been answered. Sorry I don't know the answer to your questions. If the answers to these questions are important to you perhaps you could start a new thread I'm sure someone would know this info although I suspect you may already know the answers. The answer to your question of "why" I believe has been answered in some detail. Good luck with your search.

I am not an expert on the history of scuba diving but I do know Sam Miller is considered one of the pioneers and founders of the sport. I think he is just having some fun.

 

[ajduplessis]

So he is a troll then?

 

[chrpai]

It's a good question, I just wonder if he really wants an answer of if he's just trying to make everyone look bad.

Along the lines of my "conventional wisdom" thread.... assertions always need to be understood. I found references to where 60' and 30' came from but I couldn't find the original work that came up with the safety stop recommendation. I'm not a pro, I don't work for DAN, DSAT, Navy BUMED... short answer... I don't know.