Why would you want to dump weight?

[miketsp]

The one time out of thousands of dives it was necessary for me to get to the surface NOW to survive I went from about 160' to the surface in less than 15 seconds. No DCS was involved ....

FT

No DCS involved?
How long had you been at 160' ?
Can only assume it was for a short period and you didn't have too much dissolved gas.

The one time I really had to come up fast from depth I had just descended when a diver in panic ascended like a rocket and I followed to help. When I looked at the vertical computer profile afterwards I figured I got away with it because I had almost no bottom time.

 

[MikeFerrara]

There are a bunch of reasons to dump weights, most of the time those are going to be near or on the surface.

Rapid ascents to not alwyas result in classic DCS. Pneumothorax (busted lung) is a symptom of poor airway control, not a function of ascent rate.

Lung overexpansion injuries might be a function of poor airway control but the faster you ascent the harder to adequately control the airway it is. A little conjestion that you don't even know you have may be a problem...or swallowing.[/QUOTE]

I've dumped weight in emergency situations several times. The thing to remember is that the FIRST TIME in the dive you think about dumping weight is the time to do it. Most will try to not dump and get themselves much deeper into trouble to all the way to panic. Lead is cheap. Get rid of it if you even suspect you''ll have a problem.[/QUOTE]

I've never seen that but I have heard of divers blowing for the surface and getting there dead.

The one time out of thousands of dives it was necessary for me to get to the surface NOW to survive I went from about 160' to the surface in less than 15 seconds. No DCS was involved and the lungs held up fine. Of course back in the dark ages emergency ascent techniques were taught and drilled into us. They no longer are drilled by any of the major instruction players, most don't even mention them.

FT

I wouldn't call it drilled but I'm not aware of an agency that doesn't teach divers about ESA's and emergency buoyanct ascents. Every OW class that I know of required divers to practice and demonstrate an ESA in both confined and open water.

 

[String]

Lets hear the exact descriptions of why you said you had to dump weight to get to the surface.

As ive said above, i cant see any possible situation where its the best course of action possible so interested to see if you can give me a reason.

 

[pasley]

What I learned in my initial training was to keep oneself out of trouble. The old maxim was that one cannot get bent on one 72ft3 tank. This is, of course, not always true.

Don't know who taught you that, but it is simply not supported by the facts or any certifing agency I have heard of. Divers get bent diving AL80 (or 72 Cubic Feet) tanks all the time. I know I did.

Why do you end up with DCS if you "dumb" (sic) weights? Isn't recreational diving designed to keep one out of deco situations?

If you are a recreational diver, the uncontrolled ascent is the last thing to do in an emergency. Nevertheless, you should reach the surface and not suffer any effects. ...

Yes it is. But non-Deco diving is NOT non-DCS diving.
Even in recreational non-deco diving you have gas dissolved in your blood. We S-L-0-W-L-Y ascend to give the gas time to come out of solution with the gradual decrease in pressure and off gas harmlessly. A rapid assent may result in DCS or an embolism even from a dive well under the recreational limits. DCS is not limited to long deep dives. Almost any dive can have DCS if the ascent is too rapid.

DCS or an embolism can occur on any recreational dive. Even if you do every think right, you may still take a DCS hit because there are many factors and we still do not know all there is to know about it. It is a risk we take as divers. Bottom line is that even recreational divers who do NOT make a rapid ascent may suffer DCS. Been there done that, took the ride.

 

[FredT]

No DCS involved?
How long had you been at 160' ?
Can only assume it was for a short period and you didn't have too much dissolved gas.

Spearfishing should usually be done on a no decompression basis. Bottom times deep are almost always short.

The experience has been posted on this board in the "have you almost met your maker" thread.

 

[FredT]

I've never seen that but I have heard of divers blowing for the surface and getting there dead.

I wouldn't call it drilled but I'm not aware of an agency that doesn't teach divers about ESA's and emergency buoyanct ascents. Every OW class that I know of required divers to practice and demonstrate an ESA in both confined and open water.

Recently trained recreational divers blowing to the surface are usually in panic mode by then. Airway control in panic mode is non-existant.

ESAs are different from the "blow and go" ascent techniques we were taught. Those can get you to the surface still breathing starting with empty lungs and no tank! I did that several times back in the days when SPGs and BCs were still a dream. The deepest I've done under those conditions was from 138'

FT

 

[String]

When did they define recreational diving as dives not involving a decompression obligation ?!

 

[garyfotodiver]

Don't know who taught you that, but it is simply not supported by the facts or any certifing agency I have heard of. Divers get bent diving AL80 (or 72 Cubic Feet) tanks all the time. I know I did.

Didn't write the one-tank rule was taught in any class, merely that it is an old maxim. I wrote that I was taught to stay out of trouble.

Yes it is. But non-Deco diving is NOT non-DCS diving.
Even in recreational non-deco diving you have gas dissolved in your blood. We S-L-0-W-L-Y ascend to give the gas time to come out of solution with the gradual decrease in pressure and off gas harmlessly. A rapid assent may result in DCS or an embolism even from a dive well under the recreational limits. DCS is not limited to long deep dives. Almost any dive can have DCS if the ascent is too rapid.

DCS or an embolism can occur on any recreational dive. Even if you do every think right, you may still take a DCS hit because there are many factors and we still do not know all there is to know about it. It is a risk we take as divers. Bottom line is that even recreational divers who do NOT make a rapid ascent may suffer DCS. Been there done that, took the ride.

No kidding. Sport diving is a risky sport. There are many issues involved if one suffers DCS. But all this is rather off the original subject, which was about dumping weights. The PADI (now, no cert agency bashing, please) OW course video and book I studied last year certainly mentioned dumping weights and making an uncontrolled ascent as the last choice during an emergency.

Based what I learned originally in 1970, again in 1995, and while my daughter trained last year, I would drop weights and ascend only AS A LAST RESORT.

 

[garyfotodiver]

I didn't say or I didn't mean that if you dump the weights you will get DCS. Releasing weights underwater results in a much too rapid ascend and this may cause DCS.
Mania

Mania, here's what I lifted from post #5. There are emergency situations that you would have to dumb weights and as a result ascend in uncontrolled way. You end up with DCS but with a chance to survive rather than die underwater.
And for this you have to be able to release weights rapidly.
Mania

"YOU END UP WITH DCS". Your words sir, not mine.

Your second explanation is more correct. An uncontrolled ascent is one factor that may contribute to a bout of DCS. So might dehydration, certain medications, multiple dives, short, SI's, etc.

If I was a trained cave diver I doubt I would drop my weights in a confined space. If I was not trained, I'd keep out of caves.

 

[MikeFerrara]

Recently trained recreational divers blowing to the surface are usually in panic mode by then. Airway control in panic mode is non-existant.

True.

ESAs are different from the "blow and go" ascent techniques we were taught. Those can get you to the surface still breathing starting with empty lungs and no tank! I did that several times back in the days when SPGs and BCs were still a dream. The deepest I've done under those conditions was from 138'

FT

Stop, Drop, Blow and Go...before my time. Well, I guess I'm old enough but I wasn't diving then. Choices are more limited without bc's, SPG's and alternate regulators.