DIR- Generic Balancing rig with wetsuit and doubles

[LordHavoc]

Which double tank do you prefer for Tech 2 dives when you have a wetsuit on? I use Steel 100's for my drysuit diving but dont want to swim up with the weight in case of a wing failure. Do you prefer AL-100 for doubles or LP 95, if your goal is to swim up with deco bottles hanging. Thanks.

 

[grantctobin]

Which double tank do you prefer for Tech 2 dives when you have a wetsuit on? I use Steel 100's for my drysuit diving but dont want to swim up with the weight in case of a wing failure. Do you prefer AL-100 for doubles or LP 95, if your goal is to swim up with deco bottles hanging. Thanks.

There’s not that many people doing tech 2 dives in a wetsuit, both from a buoyancy redundancy perspective and a thermal control perspective. Realistically speaking, there aren’t many people doing those dives on OC. I’d use a drysuit and 85s in the ocean, or if you insist on a wetsuit, a set of AL80s and sling more 80s if you need additional bottom gas.

 

[PfcAJ]

Double al80s and an al80 stage.

 

[Nick_Radov]

Where are you diving that the water is warm enough for a wetsuit at Tech 2 depths?

As others have stated, Al-80s are about the only tanks available in the US which allow for having a balanced doubles rig while wearing a wetsuit. If your wing fails near the beginning of the dive when you're at your most negative then you can ditch at least some of your stages (or hand them off to a buddy if safe to do so).

Some wetsuit divers also bring an extra lift bag in a pocket or bungeed to the side of their scooter, with the idea of clipping it to a harness D-ring as an emergency BCD. I've never tried that so I'm not sure how well it works.

 

[kensuf]

Where are you diving that the water is warm enough for a wetsuit at Tech 2 depths?

As others have stated, Al-80s are about the only tanks available in the US which allow for having a balanced rig while wearing a wetsuit. If your wing fails near the beginning of the dive when you're at your most negative then you can ditch at least some of your stages (or hand them off to a buddy if safe to do so).

Some wetsuit divers also bring an extra lift bag in a pocket or bungeed to the side of their scooter, with the idea of clipping it to a harness D-ring as an emergency BCD. I've never tried that so I'm not sure how well it works.

I was in 79-80° water below 100m in the Cayman Islands just six weeks ago.

Edited: Correction, 81°.

 

[rmssetc]

Double al80s and an al80 stage.

[Not to hijack this thread, and feel free to ask a mod to move my comment elsewhere if it's more appropriate.]

I've got no aspiration to do tech dives, but I've been watching too many online, and seeing configurations (wetsuit or dry) with what look like multiple AL80s.

I think I understand the question about having a balanced rig during the dive and not wanting to swim up excess weight in case of a wing failure, but I'm wondering about the opposite....at the end a dive with this configuration (3x AL80s), if something had gone badly and all the tanks were <500PSI, they would be about 18lbs more buoyant than at the beginning. Do you carry lead for that contingency to remain submerged at the last deco stop (plus enough weight to sink the diver, wetsuit, etc)?

From videos I've watched, it certainly doesn't look like divers have their wing 1/2 full of air (~20lbs lift) early in the dive & at depth, which implies that they are 'balanced', but would also be quite buoyant at the end of the dive if each tank was ~6lbs lighter.

In summary, I guess I'm asking how (or if) you prepare for a very large weight shift due to gas usage, without being greatly overweighted?

 

[FF / EMT]

So I’m going through this right now, but in a dry suit.
What I’m going to do next dive, is get my doubles (steel 100) down to about 500-600 psi, bleed my drysuit and my wing, and see what happens.
Ideally, I’ll be neutral, my guess with a SS backplate, I’ll probably be negative.
But I just go lt my own doubles rig and a DT45, so I’m still working out the trim.

 

[wetb4igetinthewater]

I was in 79-80° water below 100m in the Cayman Islands just six weeks ago.

Edited: Correction, 81°.

If I'm in the water for a couple hours, I still want a dry suit in those temperatures.

When I said that I'm a wimp when it comes to temperature, I wasn't kidding. I really love heat.

To answer the OP, I'd imagine for diving in a 5 mil, for any technical dives that I would do on OC, I'd probably be using AL80s doubled up. For anything more serious, my rebreather (which doesn't answer your question).

 

[PfcAJ]

[Not to hijack this thread, and feel free to ask a mod to move my comment elsewhere if it's more appropriate.]

I've got no aspiration to do tech dives, but I've been watching too many online, and seeing configurations (wetsuit or dry) with what look like multiple AL80s.

I think I understand the question about having a balanced rig during the dive and not wanting to swim up excess weight in case of a wing failure, but I'm wondering about the opposite....at the end a dive with this configuration (3x AL80s), if something had gone badly and all the tanks were <500PSI, they would be about 18lbs more buoyant than at the beginning. Do you carry lead for that contingency to remain submerged at the last deco stop (plus enough weight to sink the diver, wetsuit, etc)?

From videos I've watched, it certainly doesn't look like divers have their wing 1/2 full of air (~20lbs lift) early in the dive & at depth, which implies that they are 'balanced', but would also be quite buoyant at the end of the dive if each tank was ~6lbs lighter.

In summary, I guess I'm asking how (or if) you prepare for a very large weight shift due to gas usage, without being greatly overweighted?

If you ended up super light, you could let the stages go up the SMB line and collect them when you surface.

 

[Nick_Radov]

I think I understand the question about having a balanced rig during the dive and not wanting to swim up excess weight in case of a wing failure, but I'm wondering about the opposite....at the end a dive with this configuration (3x AL80s), if something had gone badly and all the tanks were <500PSI, they would be about 18lbs more buoyant than at the beginning.

Not quite. If you have helium in any of those tanks (as for a Tech 2 dive in this thread) then the buoyancy swing will be less. That's one of several reasons why higher helium mixes are generally better all around.

Do you carry lead for that contingency to remain submerged at the last deco stop (plus enough weight to sink the diver, wetsuit, etc)?

You need enough weight to hold a shallow deco stop with empty tanks. If you have a problem and end up short of gas the last thing you want is to be fighting to stay down. Part of that weight can be fixed in the form of a steel backplate and/or V-weight. But you should have enough ditchable weight to roughly equal the maximum weight of the gas in your back tanks. That way if you jump off the boat and your wing fails when the tanks are full you'll be able to ditch enough weight to get neutral without having to swim your ass off while waiting for the boat to pick you up again. Some tech divers try to be "slick" by diving with no ditchable weight, but I think this is not super smart.