Safety stop immediately after surfacing

[fnfalman]

Safety stops, on the other hand, are (by defintion) not required and may be ingnored with impunity. They should not be made up, in fact returning to the water to make them up puts you in danger (however slight) from bubble pumping due to the short nature of the safety stop.

I'm not talking about getting out of the water and then jump back in again.

Let's say that a new diver who hadn't buoyancy control dialed in or proper weighting done, who then can't hold a safety stop too well without hanging onto an anchor line or kelps, who tried to hover at 15-ft or so but somehow bobbed up to the surface. Can he or she simply dumped out air from BC and just sink down a few feet (say 5ft) and stayed there until the 3 minutes is up?

I understand that he or she doesn't need to do it because safety stops are not mandatory, but what are the chances of bubble pumping would happen in the above scenario?

 

[Mr Carcharodon]

Think about it this way:
Safety stops, on the other hand, are (by defintion) not required and may be ingnored with impunity. They should not be made up, in fact returning to the water to make them up puts you in danger (however slight) from bubble pumping due to the short nature of the safety stop.

Thal,

If you are that worried about bubble pumping how do the explain the frequent sucess with in water recompression? Or for that matter if oxygen was not available would taking a chamber ride be unsafe?

 

[Thalassamania]

Once you are at the surface, unless you are going back under for a goodly time, say 10 minutes or more, I'd stay on the surface.

 

[Scott L]

Think about it this way:

Decompression stops are required and if they are missed they need to be made up somehow ... and it needs to be done rather quickly. Conventional wisdom would be to follow ommitted decompression procedures within 5 minutes if non-symtomatic and to evacuate to a chamber breathing pure oxygen, if symptomatic.

Safety stops, on the other hand, are (by defintion) not required and may be ingnored with impunity. They should not be made up, in fact returning to the water to make them up puts you in danger (however slight) from bubble pumping due to the short nature of the safety stop.

I know you guys are like oil and water but this read by the fit and well vascularized one is very much germane to the thread.

Why We Do Not Bounce Dive After Diving in the WKPP | Global Underwater Explorers

 

[Thalassamania]

Thal,

If you are that worried about bubble pumping how do the explain the frequent sucess with in water recompression? Or for that matter if oxygen was not available would taking a chamber ride be unsafe?

IWR lasts long enough that bubble pumping is not an issue, but there are plenty of other issues and most divers and dive operations are not prepared to conduct IWR at a level of risk that I'd find acceptable.

The oxygen during transport is to minimize damage from the bends, it does not make the chamber ride any different except for oxygen clock considerations.

 

[Hatul]

The real point is ... there is no "correct" answer. It depends on a lot of things ... many of which will be unique to the individual and the dive profile they just did.

What are NDL's anyway? They're not some line in the sand which, on the one side you're safe and on the other you'll get bent. They're a look at all the factors that go into decompression ... including risk factors applicable to some individuals and less so to others ... and a "best guess" at what amount of risk you'll find acceptable.

My response to the OP would be "it depends on how fast you came up". Every time you dive, your body absorbs more nitrogen than it was designed for. Because the air you're breathing is pressurized, and because of the water pressure you're exposing yourself to, your body soaks up nitrogen like a sponge and suspends it in your blood and other body tissues. When you ascend, decreasing pressure in both the air you breathe and the ambient pressure of the water around you causes all that excess nitrogen to be released. If you come up slowly enough, your lungs can easily deal with the excess nitrogen that's coming out of solution from your blood and tissues and will expel it when you exhale. If you come up too quickly, nitrogen comes out of solution faster than your lungs can deal with it ... the nitrogen forms bubbles that expand with decreasing pressure ... and the chances of DCS will increase accordingly.

So if you came up at a sufficiently slow rate, then no ... I wouldn't go back down. Your normal breathing already took care of the excess nitrogen before it could become a problem. But if you came up quickly, then yes ... I would ... assuming I had sufficient air reserves to do it without adding another complication.

The question is ... how will you know what "safe enough" is? The answer is ... you won't. There's too many potential variables. That's why even the experts can't predict with any accuracy how much decompression is "safe". That's why there are so many conservative factors added into dive computers and dive tables.

So it gets back to the Harry Callahan quote ... Do I feel lucky?

Well, do ya ...

... Bob (Grateful Diver)

Yes I would go back down and do the safety stop, unless it was a shallow dive. There is no downside to this except the time and effort and potential benefit as in all safety stops.

If the need was there to do a safety stop, it's still there if you surface--nothing has changed regarding the benefit of doing a safety stop. In my mind it's a no-brainer.

Adam

 

[DCBC]

If the need was there to do a safety stop, it's still there if you surface--nothing has changed regarding the benefit of doing a safety stop. In my mind it's a no-brainer.

I totally agree. However if you do feel that safety stops are optional, you take a different view. They are either optional or required depending upon your point of view.

Personally I teach that they are required, as is a max. 30 fpm ascent rate. Hopefully my students will never consider it optional... You follow the rules, or roll the dice and take your chances.

 

[idocsteve]

Safety stops are REQUIRED and here's why.

About 20 years ago I was in Florida diving with my sister and the guy she eventually married. This guy thought he was the best thing that ever happened to diving and he had more C-cards in his wallet than credit cards, if you can imagine that.

So me, being a relatively new diver at the time, joined them on a wreck dive to about 90 feet, while my uncertified brother was snorkeling on the surface. During the ascent, I saw my brother on the surface, and figured I'd scare the bejesus out of him by coming up right under him from behind and I dunno..grabbing his leg or actually sinking my teeth into his ankle.

In my enthusiasm, I totally forgot my safety stop. Back on the boat, and for about 15 years afterwards, my brother in law would remind me of how brainless I was for risking my own life by forgetting a safety stop.

Thankfully they're now divorced and I don't have to freaking hear it anymore but every Thanksgiving vacation trip to Florida I had to hear that BS at least once.

Disclaimer- those without judgmental brothers-in-law or other pain in the A$$ friends or relatives who think they know everything about diving can disregard this post.

 

[Thalassamania]

If a safety stop was required, it'd be a decompression stop ... and that's an entirely different question.

 

[Buoyant1]

If a safety stop was required, it'd be a decompression stop ... and that's an entirely different question.

That would be my way of thinking...If you don't exceed your NDL you aren't REQUIRED to take a safety stop. That's why it's called NO DECOMPRESSION LIMIT. The time limit you can dive to a specific depth without needing to do a DECO stop. (which of course is theoretical)

Does that mean to blow off your safety stops because they aren't necessary? No...every little bit helps! Does skipping it mean you're going to get bent? No, but taking the safety stop doesn't guarantee it either. I err on the conservative side whenever possible. My advice to the OP is if you are already at the surface, and it's not a MANDATORY DECOMPRESSION STOP, end the dive, and do better next time.

Usually anything over 80-90 feet we always do a deep stop as well at half of our maximum depth for a minute or two, then 3-5 at 15-20 and a nice slow ascent from there. (follow your smallest bubble up, was some advice I once got)

Good luck!