safety stop on a shallow dive

[spanky]

My question do you need to do a safety stop on a dive of 30 ft. I dove on saturday morning off the coast of new england [cape ann] .The dive was a beach dive of max 30ft for about 45 minutes.We did a regular ascent (no safety stop) to the surface only to realize we went out to far we kicked are way back to the beach on the surface because I was down to about 500 psi it was a most uncomfortable situation. When I got back to the beach my righthand index finger hurt (dont recall banging my finger) by the time I got home my finger swelled up.The next morning I iced down my right hand for about 20 min after removing my hand from the bag of ice I noticed that part of my hand below my index finger swelled up also. I'm going to have it looked at but I would feel better with a response from the board.

[Neils]

An ounce of prevention is worth a pound of cure...
IMHO it is a good idea to get into the habit of a minimum 3 min. safety stop at 15 fsw on EVERY dive.

[Bob3]

Swelling isn't a typical symptom of a hit, I'd suspect either an allergic reaction to something you got into or perhaps your circulation may have been impaired by tight gloves/cuffs.
It's more common for nerve impairment to appear in the little finger & forearm first.

[Spectre]

Originally posted by spanky
We did a regular ascent (no safety stop) to the

When I was diving on tables I didn't to many safety stops when shore diving, as the ascent is so incredibly slow as I head towards shore. Now that I have my computer, I tend to listen to it's safety stop. As I'm working my way back to shore, when I hit about 17 ft my computer kicks into safety stop mode, so I just work my way along to 13 ft in those 3 minutes peaking into all the little cracks and crevices. If I make it to 13 ft and I still have stop left, I just tell my buddy to wait a minute and we hang out there until my computer clears.

When I got back to the beach my righthand index finger hurt (dont recall banging my finger) by the time I got home my finger swelled up.

Same thing happened to me at Folly Cove during a night dive last fall., and after thinking about it for a while I remembered harassing a lobster a bit and swiping my hand away from it pretty quickly and bopping a rock. When I looked at my left index finger knuckle, sure enough there was an urchin spine tip broken off in the skin...

So when the swelling goes down, check if you have any black dots or things looking a little like a splinter... not a big deal, just a little annoying.

[danceswithoctopus]

I agree that an ounce of prevention is worth a pound of cure. We do safety stops on every dive, and like Funky there we usually hang at 13-15 feet on shore dives and just poke around. (There are also many dive sites around here where one can find oysters at that depth in the right tidal conditions--good opportunity for a deco-snack!)

[Mike Newman]

You can't beat the advice given in all training - stay well within recommended limits. If that means a stop on a shallow dive - so be it.

I don't ever want to know what it feels like to be bent. How about you?

[Dr Deco]

Dear Readers:

Those safety stops are a good idea. It keeps the micronuclei small and therefore they have a high internal pressure. That means that they will not grow with the low inert gas supersaturations found in the tissue of recreational divers. One omits the staops at their own peril.

I have never had “the bends” so I cannot say how it feels. I did become paralyzed once in a laboratory study. Luckily I was recompressed within a couple of minutes and nothing more occurred. One should keep in mind that it is more than “how it feels.” The painful sensation is not always that great, but it does mean a detour to go to a chamber and treatment can be a BIG expense. (Always, it is best to have diver’s medical insurance.)

If you thought that hanging out for a few minutes on a deco line was bad, it is nothing like the time in the chamber for a treatment!
:box:
Dr Deco

[BRW]

Just some comments -- stops in general. All this
comes from considering gas seeds in the body that
may get excited into growth by any kind of compression-decompression from some semi state
of equilibration at one given ambient pressure.
The why, when, and how are too long for this posting -- but see TDID for instance.

According to "half correct" deco theory (Haldane dissolved gas) shallow stops remove dissolved gases and are standard. According to modern deco
theory, deep stops are better as preparation to enter the shallow zone -- hence tables like RGBM etc. for deep and extended range diving. Deep stops help to restrict bubble formation and growth, while shallow stops ala Haldane staging
treat bubbles at reduced pressure. The biggest
differences here come into play with deep and deco
diving, not recreational diving. WKPP, NAUI Tec
Ops, and LANL Countermeasures have been diving the new (dual phase) RGBM way to stage divers for many years now. NAUI has just released a set of RGBM
tables for recreational diving (no groups, no calcs, no fuss), and the mixed gas, deep stop, deco versions for tec, military, scientific,
commercial diving is coming -- tested and validated on the extreme envelope. Recreationally, RGBM comes into play for repets,
reverse profile, multiday, FAD in a natural way
that can be locked onto earlier tables, meter algorithms, software, etc. But on the tec side,
all is new ground and the old Haldane stuff goes out the window -- where it should have gone even a
century ago.

Safety stops for dives in the shallow zone
(down to 30 fsw) are not really necessary -- but
a good idea to slow ascents. From depth, deep
stops and shallow safety stops work together. Deco divers generally switch to high oxygen mixes in the shallow zone, add some time to required stops
in the same zone, and come up at 1 - 2 fsw/min
from their last deco/safety stop. With deep
stops first, the time in the shallow zone is cut
down, with overall deco time LESS than that
required by Haldane lore.

For recreatational diving, you can make safety stops in the 15 fsw (shallow) zone until you run
out of air with virtually NO impact upon your
next (repet) dive, when next dive has a SI greater
that 45 - 70 minutes. Or get bored. Or turn
blue in the face.

Bruce Wienke
Counterterror Dive Team Ldr.

PS -- All this is also in Technical Diving In
Depth and yes, I wrote it. Also,
magazines like Advanced Diver and Immersed
feature nice articles on same.

[VTWarrenG]

Holy ****, Wienke's on ScubaBoard????!

How ya doin' man, it's nice to say hello to ya. Excellent post, btw -- there is far too much "recreational misunderstanding" stuff going on in this forum.

People here actually pay attention to their computers, and do things like "hang out there until my computer clears" and so on. Misunderstanding of decompression theory (and reality) abounds.

Welcome aboard -- I look forward to reading more of your posts!

- Warren