burping loop

[sea_ledford]

I can hold a 10' stop with a full counterlung in my typical deco dive set up (SF2, 3L steel on-boards, 2 al80 bailouts, AL plate, 3mm wetsuit) not much more I can get rid of weight wise. I might not be able to do it in a dry suit though, at least not comfortably. The SF2 only has a 4.5 L CL though.

The only time I've had to truly bail out, I decided to not worry about burping the CL and let the OPV take care of it. I only had 2 40's for bail out and was still able to hold all my stops. Maybe it's just my negative attitude.

 

[stuartv]

I can hold a 10' stop with a full counterlung in my typical deco dive set up (SF2, 3L steel on-boards, 2 al80 bailouts, AL plate, 3mm wetsuit) not much more I can get rid of weight wise. I might not be able to do it in a dry suit though, at least not comfortably. The SF2 only has a 4.5 L CL though.

The only time I've had to truly bail out, I decided to not worry about burping the CL and let the OPV take care of it. I only had 2 40's for bail out and was still able to hold all my stops. Maybe it's just my negative attitude.

You're over weighted in that config. Whether or not you can take any more weight off doesn't really change that fact. Though, I do know some people who have carbon fiber cylinders for their CCR, for exactly that reason and type of configuration.

When I'm doing a dive that merits 2 x AL80 for BO, I am not comfortable diving in a wetsuit. I feel like I need to dive dry in that situation, to have the redundant buoyancy.

 

[sea_ledford]

You're over weighted in that config. Whether or not you can take any more weight off doesn't really change that fact. Though, I do know some people who have carbon fiber cylinders for their CCR, for exactly that reason and type of configuration.

When I'm doing a dive that merits 2 x AL80 for BO, I am not comfortable diving in a wetsuit. I feel like I need to dive dry in that situation, to have the redundant buoyancy.

This is just semantics, but I would consider it being negatively buoyant, not over weighted. I think of over weighted as adding too much additional weight. Ultimately causes the same problems, but have different causes.

But I hear you, I had to tell one of our regular research divers he wasn't allowed to use his double 104's offshore in 4-600' of water, in a wetsuit. I didn't care that he had a redundant wing.


Drysuits are an option, but come with other down sides when the water temp is in the mid 80's and surface temps are in the 90s with 90% humidity.

 

[stuartv]

I had to tell one of our regular research divers he wasn't allowed to use his double 104's offshore in 4-600' of water, in a wetsuit. I didn't care that he had a redundant wing.

Now I'm curious. What is the reasoning behind not allowing that when he had a redundant wing? What would you allow? Only a drysuit?

 

[sea_ledford]

Primarily, he didn't need the gas in the first place. He had a great SAC rate and would come back with over 2000 psi after doing a deco dive to 150 with an hour run time. He would only get his tanks filled after 2 or 3 dives. Tanks were filled on the dive bench, so the only effort that saved him was unscrewing a DIN regulator. No reason to take a 32 lb anchor with him, when a 13 lb anchor (al 80s) would do the exact same job.

We had both AL80 doubles and Al100 doubles available, and either were better tools for the job.

 

[inquis]

This is just semantics, but I would consider it being negatively buoyant, not over weighted.

Semantics, true enough. FWIW, I think of "negatively buoyant" (and positive and neutral) as descriptions of the "current" condition, and over weighted as a lack of buoyancy that won't ever resolve, without differentiation between the specific choice of backplate, tank(s), lead, canister light, BFK, or whatever is being carried. The gear configuration (as a whole) is over weighted, and it's up to individual choice for how to make it better.

In other words, over weighted results in being negatively buoyant (and staying that way), but being negatively buoyant does not necessarily mean overweighted (in my view).

 

[PfcAJ]

Now I'm curious. What is the reasoning behind not allowing that when he had a redundant wing? What would you allow? Only a drysuit?

The time that it takes to plug in your redundant wing is about the same as it takes for you to plummet to Davey Jones Locker.

 

[stuartv]

The time that it takes to plug in your redundant wing is about the same as it takes for you to plummet to Davey Jones Locker.

That sounds like dogmatic rubbish.

What failure are you envisioning where your primary wing goes from X pounds of lift to 0 in an instant? And where you don't have a hard bottom close under you, or a wall right next to you that you could grab onto if needed?

And if that is a serious concern, why not dive with the backup hooked up? I know it's ScubaBoard Verboten, but with all the advanced skills required for deep technical diving, why is it so scary to have 2 inflators connected? If you don't hit the button on the backup, it is EXTREMELY unlikely to start auto-inflating. And if you do have auto-inflation happening and aren't sure where it's coming from, how hard is it to disconnect 2 inflators, instead of just disconnecting 1?

To be clear, I'm not trying to assert a position here. I have never dived with a redundant BM wing, nor seriously considered it for myself. I'm just trying to explore what is really and truly bad about it - from my perspective of more time and dives under my belt than the last time I saw this discussed.

I know it's OT from this thread, but the original topic seems done and, well, here we are....

 

[PfcAJ]

That sounds like dogmatic rubbish.

What failure are you envisioning where your primary wing goes from X pounds of lift to 0 in an instant? And where you don't have a hard bottom close under you, or a wall right next to you that you could grab onto if needed?

And if that is a serious concern, why not dive with the backup hooked up? I know it's ScubaBoard Verboten, but with all the advanced skills required for deep technical diving, why is it so scary to have 2 inflators connected? If you don't hit the button on the backup, it is EXTREMELY unlikely to start auto-inflating. And if you do have auto-inflation happening and aren't sure where it's coming from, how hard is it to disconnect 2 inflators, instead of just disconnecting 1?

To be clear, I'm not trying to assert a position here. I have never dived with a redundant BM wing, nor seriously considered it for myself. I'm just trying to explore what is really and truly bad about it - from my perspective of more time and dives under my belt than the last time I saw this discussed.

I know it's OT from this thread, but the original topic seems done and, well, here we are....

If the elbow pops off the wing when you hop in the water, you're goin down. That simple.

A friend of mine had a rocket ascent to the surface when his wing inflated. All the way up. And that was just with one wing. It happens fast.

 

[flymolo]

I know were trained to release pressure on the loop in a BO scenario as we ascend but opening and closing the loop has a the risk of getting water in and eliminating the option of getting back on.

If we have a reached max loop volume the over pressure relief activates and as long as we can compensate by releasing our BCD/dry suit well maintain buoyancy -even on an ascent the pressure valve will continue to release with ambient pressure changes -seems obvious; what am I missing?

i guess if your light on weight it could get tricker as you go up especially if your breathing down your BO gas

Not sure what kind of CCR you are diving but I can imagine buoyancy would get really wobbly with full BMCLs and loop.