Safety stops - depth, duration and trim

[NorthWoodsDiver]

A bit off topic from the original question but I wanted to point out some research I read about in "deco for divers". I dont have the book in front of me so I cant quote but I believe they analyzed a couple variations of the safety stop and used doppler technology to monitor divers post dive for free phase gas (bubbles).

I dont recall the exact numbers but I think they had 5 minutes at 15 feet, 1 minute at 20 followed by 4 at 10 feet, and the last one escapes me right now (sorry).

Anyway as I remember the second option seemed to be the most effective form of safety stop. I do 1 minute at 20ft then 3 minute at 15ft, and 1-2 minutes at 10 and I always stay horizontal. After you get used to being horizontal in the water it starts being more comfortable and relaxing IMO. T

 

[ShakaZulu]

If you do your safety stop vertical, your feet will decompress quicker, leaving your head compressed when you exit that water...this my lead to big head syndrome, and eventually you will become a BIG diver

 

[cooperscuba]

Thanks for the read on deep stops.

No worries. The part about standard safety stops probably being "too little, too late" on recreational depths sold me on deep stops.

Nice to know my decompression theories instructor is as bad as I thought he was......

Wasn`t me, was it?

 

[Blackwood]

If you do your safety stop vertical, your feet will decompress quicker, leaving your head compressed when you exit that water

Vertical and inverted...

 

[miked]

This brought to mind a very long, and very heated thread on the "horizontal vs vertical" issue. It was several years ago. I thought it might be worth a look, but I can't find it. Perhaps it is just as well, as it really got nasty in spots.

Can any of you "long timers" dig it up?

 

[Deefstes]

Thanks for all the excellent responses. I've learned a few things here and will definitely start implementing it from my next dive onwards:

1. I think it's a good idea to be horizontal on stops (and even on ascent) so that you can get to your buddy quicker, so that you present a bigger surface area towards the direction of motion and simply to use as another opportunity to practice neutral buoyancy.

2. I'm doing my final egress after the safety stop much too fast. Will certainly try to slow that down significantly. I've always just thought that once the safety stops is finished "ok, I'm done, let's get out of here".

 

[Thalassamania]

The point that has yet to be made is that with a 30 foot ascent rate (if you actually stick to it) safety stops are a waste of time. Safety stops were initiated back in the days of a 60 FPM ascent rate that was honored more in the breach than in the practice. Objective measurement showed that most recreational divers were making ascents on the order of 100 and even 120 fpm. The "safety stop" was invented with two purposes, the first was to slow the average ascent down and the second was to put a diver in better control of the last 20 feet of his or her ascent where the pressure change was the relatively the greatest. Will a safety stop your you? Of course not. But it not of any real help if you use a slow ascent with an ascent indicator of some sort (I use a watch and a depth gauge, ten seconds on the watch, five feet or less one the depth gauge).

But it found its way into the agencies' texts and standards and lore and now they haven't the vaguest how to get rid of it.

 

[Deefstes]

Interesting post, bust surely it can't be a bad practice. If I am in the habit of doing a safety stop on each and every dive and I can do it effortlessly without any thought to buoyancy and trim, surely that will benefit me when one day when I start having to do compulsory stops?

 

[Cabbie]

I dived recently with a couple of divers who thought it was fun to do Superman impressions from 5 metres immediately following the safety stop. Personally, I like to take my time surfacing (subject to conditions). Vertical or horizontal is usually condition-dependent.

 

[Thalassamania]

Interesting post, bust surely it can't be a bad practice. If I am in the habit of doing a safety stop on each and every dive and I can do it effortlessly without any thought to buoyancy and trim, surely that will benefit me when one day when I start having to do compulsory stops?

Go for it, but understand why you're doing it and what its purpose is. My only point is don't be concerned (as I've seen a lot of dives here on SB be) if you "neglect" a "safety" stop, it's not a required stop, it's not part of your decompression, you will not get bent without it, you don't need to follow ommited decompression procedures or slap on an tank of O2 when you hit the surface if you do not do it. Yes, you're right, it's excellent practice, and I like the control that it gives you for your final few feet.