Safety stop at 15'..........always

I just want to bring this up as I had an interesting discussion with a diver in Palau recently.

I was taught that you should always do a safety stop at 15' for 3 minutes minumum. No mandatory, you just should do it for safety. If you have the air, go ahead and use it.

Our dive guides in Palau on the Eco Explorer said at every dive briefing....3 minute stop at 15'. They would inflate a marker on a rope and stay there at 15' while each diver joined them on the stop before going up to boat. Every dive this was done.... but we had one diver who refused. When asked about it he always said his computer (a very old relic I wouldn't trust) didn't tell him he was in "deco" so why would he do a deco stop. Well, several of us tried to explain that we weren't in deco either, it was just a safety measure. He didn't care, wasn't trained to do "deco" stops, so he wasn't going to do them. (this was also the only person not diving nitrox for the week... he didn't see any reason for that either.)

Now the diving in Palau is intense..... many dives were 100' deep or more. I think someone is really stupid not to stage a bit on the way up. My rule is that if I am at over 90' I will always do a few minutes or more at 45', then another stop at 15' for about 5 minutes - even if my computer says I am fine. I would rather be safe than sorry. If I have the air, I am going to use it effectively.

Anyhow, this isn't the first time I have watched a diver skip safety stops after deep dives. How many of you do Safety Stops regardless of what your computer says?

robin

I do simply because it is another way of shading the odds against DCS. I have my computer set so that 15 feet is the last deco stop should I be doing a deco dive, so it has simply become a habit for me. Remember that dive tables are a model of theory and the variables playing into them are substantial...i.e. depth, and how long at depth, condition of the diver, workload of the diver, and on and on and on.

Having said that, if I am doing one dive, it's to 30 feet and I am done for the day, I might have a tendancy to view it as non-essential....but I try and keep to a consistent routine.

Always do them.

however. I stop at 20 feet for 2 minutes then 15 feet for two minutes then 10 feet for one minute. i do this to maintain skills and holding stops with out holding a line. if in current..that is a little different I would hang on a line if possible or a rock depending where I am and what type of dive it was.

When I do go deep on a recreational dive I will do a multilevel dive plan and make a very slow acent at planned depths then holding stops at 20 feet 15 feet and then 10 feet.

Also depending on the dive and the amount of gas left...I will slowly swim around or drift as I am off gassing..

but that is just me.

Always do them just as a precaution, and often much longer than 3 min if I'm on a shallow slope where I can continue filming on my "stop." 46 years of diving and I've never been kissed... er, I mean bent!

robint:

My rule is that if I am at over 90' I will always do a few minutes or more at 45', then another stop at 15' for about 5 minutes - even if my computer says I am fine. I would rather be safe than sorry. If I have the air, I am going to use it effectively.

Click to expand...

I don't do "safety stops" per se. Instead, I do a very gradual ascent from 30 feet to the surface - 30 seconds each at 30, 20, and 10 feet respectively, and then 30 seconds to ascend between each of those depths. The "total ascent time" for this procedure (three minutes from 30 feet) is about the same as what most divers do as their safety stops - it's just done in a slightly different manner (i.e. more spread out, depth-wise). The nice thing about this approach is that it can even be used on dives that are shallower than 30 feet (i.e. you omit the 30 foot "stop" and just pick up the ascent profile during the 20 foot stop).

On deeper dives, I typically do a brief stop in the 50-70' range, and then slight pauses every 10 feet on the way up until I hit 30 feet. These so-called "deep stops" are kind of like a "safety stop" for the fast tissue compartments, which are usually the controlling compartments on deeper dives. Stopping for more than a minute or so is typically not recommended, since you are actually racking up more nitrogen loading on the slower compartments while you are stopping.

It sounds to me like you are doing something very similar to what I do (except I do not stay so long on the deep stops), so no arguments from me.

I always do at least a 3-minute safety stop, no matter what, and a 1-minute deep stop. Some dive operators, like Ocean Frontiers, are now calling for 5-minute safety stops on deep recreational dives.

Why not use the time to practice skills? I do buddy breathing, doff & don, etc., to pass the time.

Divers who learned before 1970 may not be in the habit of doing safety stops.

I once dived with a guy ... someone fairly prominent in our local diving community ... who skipped our safety stop. We were diving off a local charter, and when I stopped he just went to the surface and waited for me. When I surfaced and asked him why, he said he didn't do safety stops on direct ascents because it wasn't really required ... I didn't say anything, but I suspect he didn't do them because he didn't have the greatest buoyancy control and probably couldn't hold one if he needed to. It's been a while since I dived with him.

The 3-minutes at 15-feet thing is really a rule of thumb ... whose purpose is to allow your tissues a little time to "catch up" to the decreased pressure and offgas in a relatively safe manner. You can accomplish the same thing by moderating your rate of ascent without actually making the stop ... but it requires a bit more skill and self-discipline. Depending on the dive profile and who I'm diving with, I may do the classic safety stop or I might just do a really slow, but continuous ascent from 30 feet (usually taking five minutes or longer). They both accomplish pretty much the same thing ...

... Bob (Grateful Diver)

I don't recall being trained to do a safety stop when i was certified in 1987. I remember it becoming the standard locally shortly after that

I always do them. If it's a deep dive, I'll also do a 1 min deep stop at 1/2 max depth. While diving local quarries and lakes, the last 5-10 minutes or longer are often in the shallows in the 15-20' range. This is my safety stop. It doesn't necessarily have to be hanging there in mid water doing nothing. Heck, some of our quarries are shallow enough that the entire dive is one long safety stop!

Tables are based upon decompression theory theory that has many concomitant variables. I don't want to be an example of the 1% of cases where you end up with DCS even though you "did everything right." I'd rather be cautious. If I have the air, and I make sure I always do, I make the last part of the dive a slow, leisurely ascent. What's the rush?

Even in technical diving, in doing gas management we add the 3 minutes into whatever our deco obligation is at 15 feet. Technically, we don't need to calculate the 3 minute stop on deco gas (higher O2% instead of air or back gas), but we usually still do just as an added measure of conservatism. In 9 years of diving, I have never missed a safety stop including the 3 minutes added on to deco at that depth. I don't plan to start skipping the 3 minute safety stop, and I don't recommend it to anyone else.