BCD Failure

[johndiver999]

6:40 or so, he is holding on the line, maybe taking a little rest. Not a big deal, just thought it was funny that he grabbed it for the video that was created to prove an ascent line is not needed. I'm sure he didn't need it.

Incidentally, I think it is great that people are taking the time and effort necessary to find out how much lead they can swim off the bottom.

 

[The Chairman]

My aim, as I weight myself for a dive, is to be in a balanced rig and able to dive with no air in my BC. None, nada, and squat. I took it to extremes lately and don't even have a bladder on my BC. Not everyone notices, but when they do, it can be funny. This past weekend I was at a local spring where an instructor had a class of two. One of the best things about a BC is buoyancy after the dive. It's the one thing I miss and I carry a sausage for just that. Anyway, at a spring, there's really no need to buoy up... I just sit/stand on a rock. The instructor noticed that I wasn't inflating, and asked me about it. Said I looked like a really competent diver, but that I should remember to inflate while on the surface. I said "with what?" and showed my back. The discussion was kind of funny, especially when I admitted to being an instructor. What complicated it further was I was using an LP120. Still, I was diving a balanced rig. I had complete control top to bottom with simply my breathing.

Don't get me wrong: BCs are awesome. They provide a level of easy control during the dive and are a safety device, especially after the dive. I teach and use them all the time. Just don't let them become a crutch that allows you to overweight yourself.

What do I mean by that? First, let's talk about a balanced vs unbalanced rig. A balanced rig is one I can breathe/swim-up at any point during the dive. If you have to add weights to sink, by definition it's a balanced rig... up unto the point you make it unbalanced by adding too much weight. IOW, you shouldn't have to drop weight to swim it up. In fact, a deep breath and you should be on your way up... but if you run out of air, then simply kicking should be adequate.

In contrast, an unbalanced rig is too heavy for you to easily swim up, much less breathe easily from the atmosphere while at the surface. You'll have to add air or drop weight to get to the surface. This is not good. Sub-optimal. Bad for your health should your BC bladder break.

Unfortunately, BCs, especially the bigger ones, can compensate for most unbalanced rigs. It's easy for a diver to convert a safety device into a death trap, requiring them to do things like drop weights, the entire BC or simply drown. It's important to not splash with an unbalanced rig without sufficient buoyancy backup. I dive with a double bladder BC, a drysuit, or safety sausage(s) in order to achieve such redundancy when diving doubles and such.

Unfortunately, #2, divers rarely prepare for worst-case scenarios. They plan their dives as if nothing will go wrong and often have to reinvent the wheel when the crap hits the fan when things fail. Dropping weights is always an option, especially if you done over-weighted yourself. In 50+ years of diving, I've never had to drop my weights. I hope this helps...

 

[Ayisha]

- It was serviced about a year ago, and was not used between then and this trip...

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.

My inflator hose fell off twice when getting into the water right after a BCD service when I was a newer diver. The first time, the o-ring fell out into the water. The 2nd time, the o-ring was salvaged for a moment, then lost as the assembly was being screwed back on (I learned not to replace it while in deep murky water, and to keep spares).

An instructor who was on the dive advised me to not service my gear so often and "if it ain't broke, don't fix it".

When I complained to the LDS that it was the 2nd time the inflator hose fell off right after service, they said it was my responsibility to ensure all the valves were finger-tight before going diving - even after service.

Anyway, I learned to check my valves and connections regularly, if not before every dive.

 

[Ayisha]

How many divers can maintain neutral buoyancy with an near empty tank at 5m?...

A better question is, can you maintain neutral buoyancy at 3 m/10' with a nearly empty tank and empty BCD, and then make a slow, controlled ascent to the surface?

Doing a last check at 5 or 6 m doesn't tell you if you're underweighted.

...I honesty cannot so additional weight is required...

Which means without that additional weight, you would have been underweighted holding a stop at 3 m, and I know that you know that.

It's interesting how DIR concepts get tweaked, but lose their benefit in the process. It's meant to test an extreme, like if you had to deal with an emergency or incurred unexpected deco, you should not have to deal with a runaway ascent due to using part or most of your reserve. That's why it's tested with an empty BCD, a nearly empty tank, at the last stop you might need to hold, and still with the ability to ascend slowly and not pop up to the surface.

 

[SlugLife]

My inflator hose fell off twice when getting into the water right after a BCD service when I was a newer diver. The first time, the o-ring fell out into the water. The 2nd time, the o-ring was salvaged for a moment, then lost as the assembly was being screwed back on (I learned not to replace it while in deep murky water, and to keep spares).

An instructor who was on the dive advised me to not service my gear so often and "if it ain't broke, don't fix it".

When I complained to the LDS that it was the 2nd time the inflator hose fell off right after service, they said it was my responsibility to ensure all the valves were finger-tight before going diving - even after service.

Anyway, I learned to check my valves and connections regularly, if not before every dive.

That LDS is full of **** and put you in more danger, than if you hadn't gotten your equipment serviced. There's no harm in checking those valves, but it's not something you should normally need to do.

I hope that you you also (1) learned the lesson to never use that LDS again to service your equipment, and then (2) left that shop a very scathing review online.

It's a massive safety issue for other divers, if people continue to use that shop for gear-service.

The majority of divers are only taught a few basics around checking their own gear in your standard OW or even AOW class. I didn't realize you could unscrew the inflator hose and dump-valves on a BCD, or that regulator-sets were a bunch of individual components that could be reconfigured for my first 8 months of diving. The only interesting thing I was taught like that was "breathe out, then in to check your 2nd stage diaphram" in my AOW class. Of course, I heard over and over to "have equipment serviced annually with a certified service professional, and don't do it yourself."

Now, I actually do service my own equipment now, and would not recommend it to the majority of divers. But I do think it would be a valuable lesson for divers to know some basics, like swapping hoses, replacing o-rings, checking things are appropriately right, how their equipment is generally assembled, etc. Past that, a basic partial disassembly of a 2nd stage for basic cleaning is also a good exercise.

 

[Ayisha]

...I hope that you you also (1) learned the lesson to never use that LDS again to service your equipment, and then (2) left that shop a very scathing review online...

Well... After my mouthpiece also fell off twice right after service, I stopped going there.

I took the regs back the first time the mouthpiece fell off, they actually took them back for an overhaul. The mouthpiece fell off again the next dive in Belize, and the boat DG cinched the zip tie tight.

The owner had stopped doing the service, others were doing it, and other divers were having similar maintenance issues. That was at least 16 years ago, many people knew, and many of us started going elsewhere.

There have been few shops I trust with my gear ever since.

 

[Centrals]

A better question is, can you maintain neutral buoyancy at 3 m/10' with a nearly empty tank and empty BCD, and then make a slow, controlled ascent to the surface?

Doing a last check at 5 or 6 m doesn't tell you if you're underweighted.



Which means without that additional weight, you would have been underweighted holding a stop at 3 m, and I know that you know that.

It's interesting how DIR concepts get tweaked, but lose their benefit in the process. It's meant to test an extreme, like if you had to deal with an emergency or incurred unexpected deco, you should not have to deal with a runaway ascent due to using part or most of your reserve. That's why it's tested with an empty BCD, a nearly empty tank, at the last stop you might need to hold, and still with the ability to ascend slowly and not pop up to the surface.

I have no problem with neutral buoyancy at 5m with near empty tank/bc. As the question at 3m?
First of all I would not let myself to reach 5m with an near empty tank. Because I always reserve some of my gas for the buddy. And if the unthinkable happens I just have to find ways to slow down the ascent. But it will not be uncontrollable.
Optimum/minimum weight is for divers who are interested on number.

If the diver is underweight in the beginning of the dive then there would be issue at the end of it.

 

[rx7diver]

There's no harm in checking those valves, but it's not something you should normally need to do.

I disagree. Function checking the integrity of his/her rig is something every diver should do before every dive, IMHO. This includes checking the valves and connections on his/her BC. And checking other things like zip ties on his reg mouthpieces and on the corrugated hose for his power inflator. And more.

Even after his/her gear has been professionally serviced.

Especially after his/her gear has been professionally serviced.

ETA. This was stressed in the open water cert course I took. In fact, we had a mandatory half-day pool session (called the "Gear Check-out") a couple of days before we left for the open water part of the course, devoted to this.

rx7diver

 

[Ayisha]

I have no problem with neutral buoyancy at 5m with near empty tank/bc...

It was your question, and you said that you could not:

How many divers can maintain neutral buoyancy with an near empty tank at 5m? I honesty cannot so additional weight is required.

 

[Blackcrusader]

Good that he was wearing sufficient ditchable weights and was able to ditch them.
It's so important to be correctly weighted. rx7diver

I was with a diver deeper than 30m when his BCD failed. I used my DSMB to bring him to the surface. You can dual purpose a lot of gear.