Your BC fails now what??

[Meister481]

Are there any Tech agencies that don't teach bag deployments? I was taught this in a recreational deep class. I may be wrong but it seems to me that the OP would have the proper training for this eventuality had he completed a deco class? I was taught 3 is 2, 2 is 1 and 1 is none.

I don't mean to be critical, just wanting to clear this up for myself.

 

[Melicertes]

whats the link. I'm not finding what I'm supposed to when searching for balanced rig

Check out:
http://www.scubaboard.com/showthread.php?t=161304&highlight=Balanced+Rig

 

[Sharky1948]

If you are on deco dive, carrying deco cylinders would you not be overweighted for most of the dive and need to use your bc? I am not trying to troll, but when I see photos of technical divers with doubles and several deco cylinders I cannot help to think they are overweighted. From my understanding (if wrong correct me), cave divers drop their gas in the cave while wreck divers carry the gas throughout the dive.

Personally, I wouldn't even consider diving doubles plus stage/deco cylinders without redundant inflation.

 

[Gary D.]

Just revert back to the days when the BC wasn't even invented yet or even widely used. If it doesn't work it's no big deal. Now go get some sleep.

And I'll bet the BC came into vogue during SB's youngest members lifetime. They haven't been around that long.

Gary D.

 

[Sharky1948]

whats the link. I'm not finding what I'm supposed to when searching for balanced rig

From my understanding (which I'm sure could be expanded upon) a balanced rig is one that:

1) Will be neutrally buoyant at 10' with 500 lbs remaining in the cylinder
2) Has weight distributed between weight belt and rig in such a way that each is as close to neutrally buoyant as possible

Any corrections/amplifications?

 

[Adobo]

Not sure about this aluminum thing either. Where I'm from we use double steel tanks for tech diving. The aluminum tanks are for the stage bottles. So not so obvious to me either.

Nothing wrong with diving double steel tanks with a drysuit as far as I know. The same rig in a wetsuit is a whole 'nuther issue.

 

[JeffG]

Check out:
http://www.scubaboard.com/showthread.php?t=161304&highlight=Balanced+Rig

Thats not a real good example or thread about balanced rigs.

Here's the short form.

A balanced rig is one that you can swim up from any depth. This can include dropping enough equipment to get yourself in a state that allows you to swim up your rig.

Using some double steel tanks with a wetsuit could create a scenario when the tanks are full (ergo they are at their heaviest state) and your wetsuit has compressed and lost all of its buoyancy, and you would not be able to dump enough stuff to swim the rig up.

 

[KMD]

whats the link. I'm not finding what I'm supposed to when searching for balanced rig

The basic idea is that when you are in a heavy wetsuit that will compress at depth and lose bouyancy. Add on top of that the weight of the air in the tanks (could be upwards of 18 to 20 lbs) and you could have a rig that you cant swim up at depth.

 

[Sharky1948]

Thats not a real good example or thread about balanced rigs.

Here's the short form.

A balanced rig is one that you can swim up from any depth. This can include dropping enough equipment to get yourself in a state that allows you to swim up your rig.

Using some double steel tanks with a wetsuit could create a scenario when the tanks are full (ergo they are at their heaviest state) and your wetsuit has compressed and lost all of its buoyancy, and you would not be able to dump enough stuff to swim the rig up.

Much better explanation than mine! Thanks!

 

[Charlie99]

Just revert back to the days when the BC wasn't even invented yet or even widely used. If it doesn't work it's no big deal. Now go get some sleep.

That's what I did when my BCD failed to hold air on a 130' wall dive.

Apparently the pull dump got snagged or somebody manhandled it on the boat. It was working that morning, but when I added some air around 65' to slow my ascent it bubbled back out and my descent sped up again. Only after repeating this cycle again did I fin to stop and check things out. I found that the pull dump was stuck open. Inspection after the dive revealed that the pull dump wire cable was broken and stuck beneath the dump valve, thereby holding it open.

Although I was negatively buoyant it was well within the range of my control, so I went ahead and went down the wall of Molokini to 130' to look at the shark condo. I did find it more convenient to then ascend to up around 50-60' where, with a full full lung, I was almost up to neutral buoyancy. Had I really needed to I could have stayed at 130', although it would have been enough work that the dive wouldn't have been enjoyable.

This was with a 5mm full wetsuit. Someone with two layers of 7mm would have to work a lot harder. Someone just wearing a 3mm shorty or other thin wetsuit would find it really easy.

It's pretty easy to do a drill to see how difficult it would be for you to have a BCD failure --- simply empty all of the air out of your BCD while at depth with a nearly full tank and see how hard it is to hover and ascend.

Charlie Allen