BCD Failure

[SlugLife]

So how much weight was he carrying? How big is he? What was he wearing (besides khakis)?

My daughter had a BCD fail in the same spot--broke, not just unscrewed. We believe hers happened at depth. Neither of us noticed when it happened. I saw it when she signaled she was down to 1000 PSI.

We had performed a weight check at the beginning of the dive. She was just right at 8 pounds with a 5 mm wetsuit.

She was able to ascend by changing her aspect in the water and slowly finning. She had no trouble maintaining proper depth at our safety stop, and it required only gentle kicking to stay afloat once we surfaced.

I don't have any problem with his response--using the SMB while sinking would have been difficult. However, my general sense is that if dumping weight is the right answer to an emergency, the diver is almost certainly overweighted.

Overweight/underweight is the in-topic recently.
Don't jump to the conclusion too quickly.
Have you ever tried to float with half a full tank and the bc taking in water?
Dumping weight in that situation was the ONLY way.

I'm going to have to size with Scraps, that the initial logical assumption should be that the person in the story was over-weighted & I think I said so in an earlier reply to this topic.

• The standard weight-checking procedure at the beginning of a dive, should have you slightly positively buoyant with 80% lung capacity, and should have you slightly negatively buoyant with 20% lung capacity, at the surface with an empty BC
• The standard weight-checking procedure at the end of a dive, should have you slightly positively buoyant with 80% lung capacity, and should have you slightly negatively buoyant with 20% lung capacity, at 15 to 20ft deep with an empty BC. (edit: at about 500psi)
• Towards an end of a dive, you're even more bouyant, due to tanks being several points lighter. (by about 4 to 5 lbs)
• I've seen numerous instructors demonstrate they are able to ascend with ~80% lung capacity from depth, with no air in their BC.

It's probably unrealistic to expect relatively new divers to have exactly the right amount of weight & being under-weighted has it's own problems. However, if someone cannot stay at the surface with light-kicking & high-lung capacity at the end of the dive, it's probably safe to assume they're more than 5lbs above the ideal weight. The person in this story though might not have attempted to use lung-capacity for buoyancy, but based on how quickly they dropped at the surface would only support the idea of them being over-weighted.

I'm not super-dogmatic, that everyone must have the absolute least amount of weight possible, and understand there could be other factors or reasons why someone might carry more weight. Though if I was deliberately over-weighted (lets say, carrying spare weights due to leading a group), then I would suggest the excess weight be dumpable, without dumping all weight. While we don't have the person who experienced the problem in this thread, IMO, anyone who experiences something like this should first look at whether or not they have too much weight.

 

[Centrals]

Overweight?
How do you calculate the weight required to keep you neutral at 5m? Base on nearly empty or half or what?
If based on an near empty tank at 5m then it is overweight if there is still half a tank of gas.

 

[SlugLife]

Overweight?
How do you calculate the weight required to keep you neutral at 5m? Base on nearly empty or half or what?
If based on an near empty tank at 5m then it is overweight if there is still half a tank of gas.

500 psi. I apparently accidentally left out that detail.

That said: "I've seen numerous instructors demonstrate they are able to ascend with ~80% lung capacity from depth, with no air in their BC." is usually done with at least half a tank. For example:


The demo is at about 4:30 in the video, but the whole video is worth watching.

 

[Centrals]

No need to show any video.

Do you float with no air in your bc and with half a full/empty tank?

That diver still has 1500psi not 500 left in his tank.
1000psi and that is about 1kg.

 

[GreggS]

On our recent trip to Roatan, I had a somewhat similar situation occur. It was on the first dive of the trip. As we were getting ready to splash, as I always do, I orally inflated my BCD. However, I did not discover until I actually got into the water that the shoulder dump was stuck in the open position and all the air I had put into my BC had simply gone straight out. I couldn't hear it escaping on the boat and since I use a back-inflate BCD, I couldn't "feel" the air going in. When I did get into the water, I was somewhat surprised that I did not have enough air in my BC and tried inflating it some more. It was then that I could hear the air bubbling out of my inflate/dump valve. My wife and the DM both tried to tap on it to get it unstuck, but to no avail. I was slightly over weighted because it was the first time I had dived in salt water wearing only a skin so didn't know exactly how much weight to use and had put in a couple pounds too much. Despite this, I was able to continue the dive for a duration of 52 minutes, and held my safety stop at the end, then surface without incident by gently finning up.

I took my BC to the dive shop (we were at Anthony's Key) and they got it fixed on a couple of minutes. I also removed a couple of pounds of lead for the rest of the week. Fortunately, I was not severely over-weighted on that first dive.

I had just had all my gear serviced just before the trip. I take my BC in because I use an Oceanic Air 2, and since I had never had this issue before, it never occurred to me to check that the dump valve was stuck open. But lesson learned, I will check it from now on.

So just from my own experience, I would have to agree that the buddy in the OP was rather over-weighted. I know @jejton has said that his buddy has quite a bit of experience, and I'm glad he was able to survive the incident without panicking. But like others, I think he needs to re-evaluate his weighting.

 

[AfterDark]

Overweight/underweight is the in-topic recently.
Don't jump to the conclusion too quickly.
Have you ever tried to float with half a full tank and the bc taking in water?
Dumping weight in that situation was the ONLY way.

Indeed, if the BC was taking on water which seems likely than how much weight the diver has becomes rather academic at that point as the weight of the water continues to increase. Having lead to dump, even a few pounds is much safer IMO than trying to get one's weight down to the bare oz. Ten+ pounds is overweighed, 2lb over is smart.

 

[inquis]

That diver still has 1500psi not 500 left in his tank.
1000psi and that is about 1kg.

Yes, a whopping 1 kg -- easily compensated with a larger breath. This diver could not even SWIM up, almost certainly kicking very hard.

 

[inquis]

if the BC was taking on water which seems likely than how much weight the diver has becomes rather academic at that point

That is immaterial because the BC should be empty at the end of the dive by design. Taking on water is equivalent to a smaller BC, but it's still empty.

 

[johndiver999]

Wearing a BC which holds no air and is taking on water in 5-ft seas is not going to feel good. If the diver is low on air, does not have a snorkel on their mask and is tired from the dive and is without a buddy nearby and is contemplating dropping lead, then there is really very little question about what to do.

If a diver is in a situation where dropping lead will not cause some type of significant problem (for example an uncontrolled ascent) and is considering that option, then decisive action should not be delayed.

Problems at the surface when it is rough can spiral out of control in one instant if the diver inhales even a tiny amount of water and their throat locks up. This is one reason why removing the regulator and calling for help or notifying someone on the boat that you are having an issue can cause a serious problem. Should a diver delay immediately dropping lead in this type of situation, their future ability to do so (and function in a logical and effective manner) can be completely lost.

Sometimes I doubt that some people who make comments about the benefits of being "theoretically" neutral at the surface have ever been caught in a washing machine situation, behind a boat with their regulator out of their mouth.

Having trouble at the surface is often significantly more complex, dynamic and actually dangerous than dealing with a situation when submerged 20 feet. The psychological stress of being slammed around, waves breaking over your mouth, face and head can be significant. The diver (at least temporarily and repeatedly ) is losing the ability to see, hear and control their position and attitude in the water and if they decide to spit the regulator it can spiral downward in an instant. Even having a breaking wave loosen and partially flood a mask can be the straw that breaks the camel's back.

Of course if you are totally calm, not winded, in good shape and comfortable in rough conditions, then it might not be a big deal, but for most people, you throw in a leg cramp on top of all this and "Houston, we have a problem".

I think it is so important that people be mentally prepared and are physically capable of dropping lead if/when they THINK they need to. I hear people constantly repeating comforting phrases like "anyone can call a dive for any reason" - which is NOT really true if you are a dive professional BTW, yet seem hesitant to acknowledge some of the benefits of dropping lead.

 

[rx7diver]

I described in a SB post a long time ago one of the skills required in the open water certification course I took (in Summer 1987). The skill remains incredibly meaningful to me because I have never been a strong swimmer. I keep this skill in mind whenever I am playing with a new gear configuration (for rec diving).

The skill is meant to demonstrate how critical are proper weighting and weight configuration. The skill was designed for diving locally in MO and AR. So, a diver would be wearing (at that time) a full 1/4" farmer John (including hood) and (at that time) a steel 72.

The skill was called the "Three Mile Swim." I will find and link that old SB post when I have time. Meanwhile, the skinny is: Wearing full gear (including weight belt with the correct amount of Pb, and a snorkel), with full steel 72, and completely empty BC and no air trapped in the exposure suit, the diver had to surface swim, prone, 1.5 miles. No time limit. The "certies" swam as a group, and alternated towing the dive flag. The only requirement was you couldn't breathe off of your regulator, and no one could fall too far behind the person towing the dive flag.

Lesson learned: The skill was absolutely no big deal (save for boredom) even for a diver who was not a particularly strong swimmer! Proper weighting is critical to safe diving.

ETA: I just double-checked with the current instructor of the course I took: She reminded me that the regulator is left off completely for the "Three Mile Swim" skill.

rx7diver