Why would you want to dump weight?

[mddolson]

Weight belt ditch?
Perhapps it would help to review why we taught this in the first place. The buoyed emergency ascent is/was taught for OOA emergencies at depths too great for an ESA to be safely performed
I had to go back to some notes I made at an(1990's) Underwater Canada Conference.
The Lecturer was Dr. George Harper, MD, diver and Chief Coroner for Bruce County, Tobermory Hyperbaric Treatment Center, Ontario Canada.
(from my notes)
1) There is not enough oxygen in a diver's lungs, including the air becoming available from an empty tank during the ascent from depth around 100 feet to support a swimming ascent.
2) The swimming diver will black out due to dropping PO2 in the lungs, due to the diver using the O2 to swim to surface, and dropping ambient pressure.
3) There is however sufficent oxygen to maintain conciousness for a diver to perform a buoyed ascent.

A diver propperly trimmed (neutrally buoyant), just needs to drop his weight belt to become positively buoyant and ascend.

Yes, he will exceed the recommended safe ascent rate of 30 fpm.
Yes, he may suffer DCS, however that's treatable.

Exhaling during the ascent, keeping the regulator in his mouth, so it is clear and periodic inhales will deliver some air to the diver and reduce the risks of embolism and black out.

I do not believe these principles have changed for "SPORT" divers.

Mike D

 

[Xanthro]

And another old thread rises from the dead.

 

[devilfish]

Has anyone here picked up a real unconcious diver off the bottom, not just a simulated rescue scenario to really know how negative the diver will be, even if the diver was neutral while conscious, before making theoretical opinions?

 

[Scuba_Vixen]

Weight belt ditch?
Perhapps it would help to review why we taught this in the first place. The buoyed emergency ascent is/was taught for OOA emergencies at depths too great for an ESA to be safely performed
I had to go back to some notes I made at an(1990's) Underwater Canada Conference.
The Lecturer was Dr. George Harper, MD, diver and Chief Coroner for Bruce County, Tobermory Hyperbaric Treatment Center, Ontario Canada.
(from my notes)
1) There is not enough oxygen in a diver's lungs, including the air becoming available from an empty tank during the ascent from depth around 100 feet to support a swimming ascent.
2) The swimming diver will black out due to dropping PO2 in the lungs, due to the diver using the O2 to swim to surface, and dropping ambient pressure.
3) There is however sufficent oxygen to maintain conciousness for a diver to perform a buoyed ascent.

A diver propperly trimmed (neutrally buoyant), just needs to drop his weight belt to become positively buoyant and ascend.

Yes, he will exceed the recommended safe ascent rate of 30 fpm.
Yes, he may suffer DCS, however that's treatable.

Exhaling during the ascent, keeping the regulator in his mouth, so it is clear and periodic inhales will deliver some air to the diver and reduce the risks of embolism and black out.

I do not believe these principles have changed for "SPORT" divers.

Mike D

That would appear to be perhaps the only type of scenario where dropping weights at depth makes any sense. The truth is that there's no excuse for getting into that situation in the first place.
It's a response to a situation that divers should be much better trained to not get into.

The real illogic here is *** are you doing still at 100' (or too deep to CESA from) when your gas supply has been so used up and *** are you doing going to those depths in the first place without redundant supply? (either a buddy or onboard redundant)
It's bad enough that most rec divers feel that going immediately to the surface is the solution to any event that makes them uneasy. They see weights as what's holding them down, and then because of poor training, or stressed thinking, inappropriately ditch their weights.

If you look at the number of injuries as the result of innappropriately ditched / accidentally dropped/lost weights and compare it to the number of injuries/deaths that *not dropping* weights resulted in, you can see that the concept of lots of ditchable weight, that can be jettisoned easily, hurts far more that it helps.

Sometimes it seems to me that rec dive training teaches you more about how to get your butt out of the fire, than about how to plan and manage a dive to avoid getting it there in the first place.


Darlene