On the fast train or slow on?

[herman]

If the diver is in panic mode then all bets are off. I suspect that a paniced diver would either not dump any weight or dump the whole thing reguardless of the type of weight system he had. While having a 2 part weight system may be a easier, I don't see a great amount of time saving. Unzip pocket, pull out weight bag, drop, if the diver is in control, what are we taking about saving, an extra 3 or 4 seconds, not enough time to make a real difference to me and I would rather gamble on the loss of a little time than a wildly uncontrolled accent which is exactly what you would have with the amount of positive bouyancy you described. Wonder how far you would come out of the water when you reached the surface?? After going back and looking at your numbers, is dropping half of the weights really an issue? After all, you would still be 15 lb positive and there is no way you can control that much positive bouyancy so it appears you are in big trouble either way...Maybe an emergency lift bag is the answer. In any case, an interesting question and the kind of thing that will help us all become better divers. Keep them coming.

 

[Walter]

.........your BC should still hold some air even if punctured. That coupled with Herman's suggestions should get you safely to the surface which is the safest place to drop weights.

WWW™

 

[Iguana Don]

This happened in Cozumel during the 2nd week in Feb., a man ditched his weights at about 60' I think it was. And skyrocketed to the surface. Died in the boat with an AGE.

"Or do you think you’d be better off too just dump all your weights, become positive buoyant, and take your chances with AGE and DCS on your ride up?"

I don't like those chances at all.

ID

 

[large_diver]

Hi Warhammer,

I agree with your "make the weights ditchable in stages" philosophy. I too wear alot of weight -- about 35 lbs. I split it between my weight belt and my 2 BC-integrated pockets, allowing for more gradual dumping.

 

[DiverDave]

Herman,
There is not always an anchor line available, eg drift dives in the UK are usually done with the boat following SMBs. In these cases, the fixed line to the surface is not an option.

There would seem to me to be two reasons why you would contemplate ditching of weight:

First of these is OOA and in this case its a last resort. Here your risk of AGE is pretty high, but if you are deep without a buddy or redundancy then you knew the risks, didn't you?

The second reason would be failure of buoyancy, whether through a puncture or an LPI breakdown. Here the lift bag is an available option. The risk of that is the buoyancy of the lift bag increases on ascent. Dry suits give the diver a redundant source of controllable buoyancy. Assisted lifts with your buddy are also an option.

More of an issue is distribution of weight between systems so that accidental loss is less of an issue. I have had a belt buckle fail and lost 32lb at 24m. That ride up was terrifying and very very quick. Not one I ever wish to even contemplate happening again. Better distribution is much safer.

 

[herman]

I realize that a accent line is not always an option, ie a drift dive or shore dive, but the senerio that was presented was a wreck dive which would have one avalible. I can't imagine a drift dive senerio that would involve a ripped BC and even if it did then a close buddy is almost assured unless drift dives are done differently in the UK. Bouyancy increase in a lift bag is not a problem, some have release valves to vent air and turning it upside down and releasing some air is always an option. I agree that accidental weight loss is a more likely accident and seems to me to be a much bigger threat.

 

[JoelW]

Questions like this are one of the reasons why I am moving to a backplate. I currently use a Zeagle tech BC. I prefer not to put all of the 32# when drysuit diving in the pockets and I have had a weight belt slip to my feet when wearing a drysuit, so I don't like that option either. Now I put 20# in the BC and another 12# in 2 pockets on a ditchable weight harness. It looks a bit goofy to other people, but I am going to dump the 2 6# pockets first if I ever have the need to. I was explaining that to a couple of people while ice diving last weekend. We weren't going deeper than 60' but the headache that would result from dumping the 32# and hitting the ice would take more than Nuprin.

In the future I will just weight the backplate to half of the weight and keep the rest in the harness.

JoelW

 

[ericfine50]

Joel,

Are you using doubles or a single?
Thanks
Eric

 

[Warhammer]

I always carry my safety sausage with me, so that too is another option of getting to the surface. And probably one best option if a anchor line isn't available. Since my sausage has 40lbs of lift, is closed and has a pressure relief valve, I could essentially use it for a BC. But I didn't consider it in my senario because the issue was weight distribution.

While true that even 15Lbs of buoyancy would be hard to control, it would have to easier than 30.

 

[JoelW]

Eric,

I am strictly a single tanker. With an AL80 it takes a fair amount of weight to get to the bottom. I figure that I will be setting up the backplate to weight about 10-12# and put the rest in the harness.

JoelW