Decompression stop for shallow dives?

[Potapko]

Its just that, *suggested*. Provided the ascent rates arent violated as the manual says, its optional and will not penalise you at all if the stop is skipped.

No, I understand. It is just one of those nuisances. I understand that the Viper also doesn't automatically adjust for elevation. You have to know how high you are.
(boy, that didn't sound good)
Jeff

 

[teknitroxdiver]

OK, then you don't fall into my catagory:

mashing the deflate button all the way to the surface

If you're only dumping in small increments when you need to, then you aren't using the technique I stated.

 

[SquattingRadishDM]

I'm not sure I understand. Why is water inside the wing a problem? I always seem to surface with a few pints or more in my wing from ascending in exactly the way you advise against, but it drains out very easily, and hasn't harmed anything as yet. Are you saying I'm risking my equipment's usable life by doing this? Or is there another reason I shouldn't?

The BCD will provide less bouyancy with water inside the bladder as a lesser volume of water is displaced. Some water in the bladder will not damage your equipment provided you thoroughly rinse it out with fresh water after the dive.

On the subject of safety stops I personally do a safety stop on any dive deeper than 40'. Microbubbles (tiny N2 bubbles that can cause DCS if they grow larger) can be caused by a 0.4 bar change of pressure (4m to surface), so come up slowly even from your safety stop. Its good to practise safety stops even when they may not be strictly required by the tables or your computer. I have seen divers that seem relatively OK underwater until they get to the safety stop, and then their bouyancy control goes out the window. Having talked to them afterwards, its usually because they have mainly dived shallow and havnt done many safefy stops as their tables or computer dont tell them to. Safety stops are like any other skill that should be precticed, especially as it is an important one for safety.

Maybe the instructors out there could tell me if they practice safety stops with OW students, or if they are just talked about in the classroom.

-Jack

 

[diverbrian]

Personally, I use the inflate/deflate hose in short bursts on descent/ascent. I hate trying to find the rear air dump in wing and it is too sensitive for fine tuning buoyancy in any case. Thick gloves make finding that dump and controlling it difficult for me. The inflator hose is right in front of me. That makes my options easy. And I do ascend horizontally, I just adjust my trim on ascent to allow me to do this. Like Curt Bowen, I have seen divers afraid of the inflator hose. We have a word for them up here. That word is rototillers and they are not popular with photographers, LOL.

The others have given a good accounting of the Suunto computers and their safety stop policy. Personally, I don't have a problem with doing a safety stop on a forty ft. dive but if weather or other conditions where such that I had to blow it off, I wouldn't lose sleep over it.

I don't agree with blindly following the computer. I do feel understanding why it is telling you the things that it is telling you is imperative. Then, you might understand why it is telling you to do that extra stop. Then, you know whether it is a good idea to take the advice of the tool that you've chosen to use or take what you need and decide what to do yourself.

PS From the description that just read, I would have called that dive. That doesn't sound like any fun to me.

 

[Mako Mark]

Most BCs (hmm arent they off the list too!) have a right shoulder dump valve and a bottom dump valve in addition to the corrogated hose providing a means of dumping at any attitude. .

we have over 400 sets od dive gear where I work and not a single one has a right or bottom dump valve. Sorry string, but you are forming assumptions with limited info there dude.

Maybe the instructors out there could tell me if they practice safety stops with OW students, or if they are just talked about in the classroom.
-Jack

Do safety stops with students without fail...... (do safety stops without students without fail.....)



DAVID, it sounds like this was a pretty sucky dive and I would take Dons advice and call it. Curt Bowen asked what type of computer it was and I didnt see an answer, c'mon, let us know and we can give you better advice.

It is good that you have the attitude to gain experience cautiously and asking advice here, so dont take too much notice if the board gets a bit harsh on you or air 2's etc etc.

I would think your computer was telling you that your ascents were a little fast, and that it was suggesting a SS.

 

[Web Monkey]

The training agencies are wrong. Use your power inflator to gain slightly positive buoyancy. Once you start to rise (without kicking) drain the expaded gas out as needed to control your speed.

If the diver was neutral to begin with, an ascent shouldn't take much more than a slightly larger breath of air, followed by controlled venting of air from the BC to control the ascent speed.

I can't count the number of times I have watched a new diver pound the crap out of the reef or silt out the dive site with their fins because some instructor told them never to inflate.

Maybe fins should come with shockers that zap the diver whenever they touch something.

Terry

 

[BigJetDriver]

Multiple ascents on a dive are very BAD. Cases of shallow water (ie 10m or less) decompression illness are often associated with multiple ascents.

BD, et al,

If this were so exactly as stated, there would be dead and dying Scuba Instructors and Commercial Divers flopping on the surface of lakes, ponds, and shallow diving sites all over the place. (The general sense of it is correct, but it is a BIT overstated.) (Ed. note: Please note response by my friend Pipedope; a long-time commercial diver.)

[DavidPT40] "When you say decompression illness, are you talking about an embolism or something else? Could you please cite an article or paper I could reference. I frequently surface from around 25 feet to check my position due to currents that change with the tide. Is embolism my only worry or am I missing something. I beach dive in the 20-25 foot range for around 2 to 2 1/2 hours per dive."

As for this request, this is a very reasonable question! Try checking your __________ (fill in the blank) agency dive tables for the NDL for the depth range you are averaging. Compare that with tables from the other agencies. In that depth range your nitrogen loading is slow and low. It does NOT, however, make it risk free!

Some reading in Bennett and Elliott (5th Ed.), and Edmonds, Lowry, Pennefather, et al, would be in order to better understand the possible risks. (PM me if you need help in locating those references.)

Remember, ASCENT RATES are always critical, and the SAFETY STOP is just that. It is not REQUIRED by the algorithm, but it is always a good idea.

Just remember, as Mr. Natural always says: "Use some common sense on the job, kids!"

Cheers!

 

[BigJetDriver]

I am new to diving and even i know that what you did was reckless..

Nemisis,

We try, on this Board, to avoid responses like this. This kind of rhetoric is inflammatory, to say the least, and is rather unkind when new divers are asking honest questions to get real answers.

If you respond in this manner, it merely stops people from asking questions, the answer to which may save them from grief! (Besides, if you continue to respond in this manner, the Moderators will give you a well-deserved vaction from this Board. This is not, thank Heavens, the "rec.scuba" board!) :no

Cheers!

 

[jbd]

If the diver was neutral to begin with, an ascent shouldn't take much more than a slightly larger breath of air, followed by controlled venting of air from the BC to control the ascent speed.

That is what I teach the people I train. Although you can add a very small puff of air to the BC and get the same results.

 

[omeko]

is there an agency that teaches the use of the inflator hose to surface?? Seems dangerous to me since uncontrolled ascents wouldn't be uncommon I'd think. Help the newbie here.

CMAS actually examines an ascent on your BC solely from 21 meters upto 3 meters and staying there for deco for 3 minutes.
I actually think any diver should be able to perform this action since it is nonsense to spill energy and precious air when going up.

From the old US-Navy school: if your ascent was faster than 18m/min go to the depth where the pressure is half of the pressure of the deepest point during your dive and stay there for three minutes. I.E. 3 min on 5 meters during training this ascent.Though obsolete by modern standards this rule of thumb always worked for me.

So if your computer starts yelling at you, your ascent probably was to fast. And concerning diving in zero visibility: this is a common activity overhere and is quite allright for training selfdiscipline and learning to avoid panic.