No Ditchable Weight

[mahjong]

Currently, I have my twin PST E7-100 rig trimmed out with a 8.5# V-weight, plus a can light on the right and a 6cf argon bottle on the left. I dive with a drysuit, either a DUI TLS or DUI FLX50/50. Wearing Bare fleece plus Polartec layers, this is enough weight. When I wear my 400g Thinsulate jumpsuit, I slide a 1# bullet weight on each side of my waist strap.

So, in all configurations, I now have no ditchable weight on my twin 100 rig.

What is the DIR position on drysuit diving with no ditchable weight?

Thanks,

Paul

 

[BluewaterSail]

You need to be able to swim up from depth with no air in your wing. If you can do that, you're OK. Its called a balanced rig.

 

[mahjong]

What about drysuit? Is it cheating to add air to my drysuit if I need lift?

 

[NickPhillips]

Like BlueWaterSail said, it comes down to a total catastrophic error resulting in 0 gas avaliable being that gas argon, air, nitrox, trimix ect. So yes inflating your drysuit is cheating. The no ditchable weight IMO would be okay if you say ran out of all gasses yet were not weighted so much you could not swim to the surface.

 

[HenrikBP]

I think redundant buoyancy is part of the "balanced rig" planning. I.e. if you're diving heavy tanks, having 2 independent buoyancy devices (wing and drysuit - *not* double bladder wing ) is part of the plan. I believe the phrasing is that we plan for one major failure. So if your wing fails you can add gas to your suit in order to help you swim up.

But then I could be wrong about all that

Henrik

 

[PfcAJ]

If you've got REALLY heavy/full tanks (lp104s with nitrox, for instance) and you have a wing failure, you're gunna have a bad time without using the drysuit.

Balanced rig means a few things:

A) Be able to swim your rig up (and stay on the surface) with FULL tanks
B) Stay at ~15ft with virtually empty tanks

If you can't do that with your current setup, something needs to be changed. You (not you, the OP, but you, the reader) might need ditchable weight instead of a fixed v-weight (allowing you to drop it and make your rig light enough to swim up). Or you might need an aluminum plate. Or perhaps a drysuit (as is the case with almost all steel tanks, esp doubles) with a proper undergarment. The only way to know is to get out and test it. Everyone is different.

Don't make the mistake of trying to get too slick and end up being underweighted when low on gas. Its miserable and has the potential to really wreck your afternoon. Kludge 'solutions' for such as lift bags, SMBs, and double bladder wings are not the answer and don't qualify as redundant buoyancy in any way, shape, or form. They're all wishful thinking at best.

 

[nimoh]

I think redundant buoyancy is part of the "balanced rig" planning. I.e. if you're diving heavy tanks, having 2 independent buoyancy devices (wing and drysuit - *not* double bladder wing ) is part of the plan. I believe the phrasing is that we plan for one major failure. So if your wing fails you can add gas to your suit in order to help you swim up.

But then I could be wrong about all that

Henrik

If you are only planning for one major failure, why would the drysuit not be adequate as redundant buoyancy. If your BC and your drysuit failed, wouldn't that be two major failures?

 

[HenrikBP]

If you are only planning for one major failure, why would the drysuit not be adequate as redundant buoyancy. If your BC and your drysuit failed, wouldn't that be two major failures?

I thought that's what I wrote ... but maybe not well

"So if your wing fails you can add gas to your suit in order to help you swim up."

 

[rlynch]

Read Aj's post above.
Test is your rig with no help, actuality is you use your dry suit but dumping gas is slow but. Anyway if you can't hold a stop, bad juju

 

[lamont]

Like BlueWaterSail said, it comes down to a total catastrophic error resulting in 0 gas avaliable being that gas argon, air, nitrox, trimix ect. So yes inflating your drysuit is cheating. The no ditchable weight IMO would be okay if you say ran out of all gasses yet were not weighted so much you could not swim to the surface.

If you have 0 gas available then you should be pretty light. With a wetsuit at depth you might have crush to deal with which makes ditchable make a bit of sense. With a drysuit you shouldn't have crush to deal with unless you lose all your gas shallow and then drop uncontrollably down to the bottom or something (which is in the realm of where you shouldn't be doing this kind of diving if you can't prevent that from happening).