BCD Failure

[Ukmc]

Same thing happened to me in Oman while descending. The screw became loose and I sunk like a rock even though I kept adding air. Luckily my dive buddy noticed and tightened it.

You should never sink like a rock unless you are heavily overweighted.

 

[The Chairman]

You should never sink like a rock unless you are heavily overweighted.

Which happens with steel tanks and especially so with steel doubles.

I doubled a pair of steel HP 120s and didn't get the bands high enough. I was so head heavy, that I could not get horizontal until I hit the bottom. Luckily, it was sand and I crawled over to a ladder, hoping no one had seen my faux pax. I was still sweating when I left the water.

Another anecdote: A popular SBer went to the Keys and hooked up with a dive op that used steel tanks. She went from diving in a dry suit with AL80s to diving in a steel HP100, a bikini, and did not remove any of her weights. She died in about 20 of water fifty feet off the back of the boat. Her weights were still attached.

 

[Bob DBF]

I don't know, in my inexperienced opinion, whether he really should be faulted for dropping his weight as opposed to attempting any other maneuver.

No one should be faulted on dropping weights on the surface, if they think they are in trouble or can't understand why they are having problems staying on the surface. Once one goes into panic one will not think to drop the belt. The belt can be retrieved later. The A&I thread has many examples of divers making it to the surface, only to sink and die.

 

[Eric Sedletzky]

No one should be faulted on dropping weights on the surface, if the think they are in trouble or can't understand why they are having problems staying on the surface. Once one goes into panic one will not think to drop the belt. The belt can be retrieved later. The A&I thread has many examples of divers making it to the surface, only to sink and die.

That’s exactly right, and experienced divers too!
I’ve read some of the accident reports here in history and there was one, a lady, that came up and was on the surface only to sink away and die.
There was another one years ago involving two guys beach diving in San Diego. They were coming in and were exiting the surf separately when one of the divers’ inflator hose broke off the BC. He sank like a rock and panicked unable to find a working reg, and unable to dump weights. They found him less than 100’ from shore in 10’ of water dead on the bottom.
I don’t know about you but the first thing they always harped about when you got in trouble was to DROP YOUR WEIGHTS!!!
That was for ab diving mostly but I hung on to that for scuba too.
Overweighting kills!

 

[rx7diver]

... During the dive I thought how stupid it had been for me to leave the DSMB. What if something unexpected happened? Luckily nothing did but I learned my lesson.

[HIJACK]
A DSMB is not a critical piece of gear for rec diving, IMHO, depending. If diving where current, or overhead traffic, etc., are likely, then maybe. If a rec diver has been diving conservatively, staying well away from NDL, then slowly ascending directly to the surface, without having shot a bag from depth, omitting the (optional) safety stop, should introduce negligible additional risk to him/her.
{/HIJACK}

rx7diver

 

[Bob DBF]

I don’t know about you but the first thing they always harped about when you got in trouble was to DROP YOUR WEIGHTS!!!
That was for ab diving mostly but I hung on to that for scuba too.
Overweighting kills!

I learned SCUBA without a BC, so it was similar to ab diving only with a tank on your back. The emergency drill was drop your weights, and if still in trouble, ditch your rig and swim home. Actually, If your tank was empty, take it off your back and use it as a float, and/or tow it home as it forces you down if you swim with it on your back. You don't notice it in a 7 mil, but you will au natural, as I did when I started.

 

[rx7diver]

... Actually, If your tank was empty, take it off your back ... as it forces you down if you swim with it on your back. You don't notice it in a 7 mil, but you will au natural, as I did when I started.

I think many people don't appreciate this fact. The 3,500 psig PST HP80 and HP100 (for example) are nice cylinders, but they are negatively buoyant with an O.D. of 7.25" (versus a 2,250 psig PST 72 with an O.D. of 6.8"), and they will push you a bit deeper when you're surface swimming with a snorkel. At least, this has been my experience.

rx7diver

 

[Bob DBF]

I think many people don't appreciate this fact. The 3,500 psig PST HP80 and HP100 (for example) are nice cylinders, but they are negatively buoyant with an O.D. of 7.25" (versus a 2,250 psig PST 72 with an O.D. of 6.8"), and they will push you a bit deeper when you're surface swimming with a snorkel. At least, this has been my experience.

rx7diver

Try a Faber MP120, it's a real prize on the surface, or walking back to the vehicle for that matter.

 

[Eric Sedletzky]

I think many people don't appreciate this fact. The 3,500 psig PST HP80 and HP100 (for example) are nice cylinders, but they are negatively buoyant with an O.D. of 7.25" (versus a 2,250 psig PST 72 with an O.D. of 6.8"), and they will push you a bit deeper when you're surface swimming with a snorkel. At least, this has been my experience.

rx7diver

How about that big fat bomb of a tank the E8 130?
That sucker’s a waterheater!
The only other tank I heard about that was bigger was one Beauchat made. I believe it was a 190 that filled to 4300 or 4500 psi? It was some insane amount negative in the water, and it also weighed an insane amount full on land. I’ll try to find some info on it.

 

[SlugLife]

You should never sink like a rock unless you are heavily overweighted.

I mostly agree, except I recently started diving sidemount 2x steel 100s. Even with a wetsuit, ALL weight removed from my BCD, and near-empty tanks I still sink. I also am sometimes too lazy to remove weights from my BCD, but that's my fault.

[HIJACK]
A DSMB is not a critical piece of gear for rec diving, IMHO, depending. If diving where current, or overhead traffic, etc., are likely, then maybe. If a rec diver has been diving conservatively, staying well away from NDL, then slowly ascending directly to the surface, without having shot a bag from depth, omitting the (optional) safety stop, should introduce negligible additional risk to him/her.
{/HIJACK}

rx7diver

It's not critical, but I like having it as redundant buoyancy.