Came up too fast

[stormchaser]

Was this your first dive on that trip with that gear setup? If so, did you add more weight on the following dives? If that was not your first dive, did you have any trouble on the previous dives?

I had 5 previous dives the day before with #80 tanks full of nitrox. On this dive I was using a #100 or 120 tank of air. And yes I always had trouble with buoyancy because I was dragging bottom while upright so I had to add air to the BCD to compensate.

 

[stormchaser]

@stormchaser: Did you do a weight check after getting the new wetsuit and the 100 cubic ft. tank? How did you arrive at the 22 lbs. of lead?

No just went feet first LOL

 

[Guba]

One additional note...simply "pulling the (dump-valve) strings" might not do anything at all. If the BC isn't rotated so that the valve is at the highest point, you won't lose any air from it. The valve is open, but the air is trapped and will continue to expand as you ascend.
Glad you could walk away from this one, which is providing some good lessons to be learned.

 

[stormchaser]

Perhaps the BC inflator valve was leaking or got stuck open. It is not too uncommon with rental gear, which is one reason I ALWAYS bring my own gear. With rental stuff you have no idea how well it has been maintained. Even so, with a stuck inflator you should have been able to vent air faster than it filled the BC. I know you were scared, but did you hear any air rushing into the BC during the ascent?

No I bought all new gear. I wouldn't be comfortable in rental gear....to many bad things could happen

 

[stormchaser]

One additional note...simply "pulling the (dump-valve) strings" might not do anything at all. If the BC isn't rotated so that the valve is at the highest point, you won't lose any air from it. The valve is open, but the air is trapped and will continue to expand as you ascend.
Glad you could walk away from this one, which is providing some good lessons to be learned.

I have a feeling this is what happened. I have a dump valve on my right shoulder, one on my left shoulder (when I pull on my Aeris Air Link Inflator Octopus) and one on the bottom right of my BCD.

But I don't have a clue how the air could get trapped

 

[u2girlie]

I had the same thing happen to me last November over in Playa @ the Mama Vina wreck but I am 99.9% sure that it was my fault. At first, I thought I forgot to let air out of my bc and as we were heading to our safety stop I was becoming more buoyant. However, after subsequent dives, I realized I think I was hitting my inflate button. During the process, I was eerily calm. Hubby swam up and grabbed me and tried pulling me down but I kept rising. He was yanking on all my release valves and finally got it under control and was able to get me back down to the safety stop. (He was way more nervous than I was). Afterwards, the more I thought about it, the more freaked out I was. However, I can tell you that I have never had the happen again and probably never will. I am very, very aware during my ascent that I have released all the air and that I'm not inflating. Almost to the point of being neurotic but I'm a firm believer that what doesn't kill us makes us smarter!

Oh and as someone else said, no more rental gear for me. I'm buying my zeagle zena before our next dive trip so I can become intimate with the set up!

 

[dmoore19]

Just a comment, as you became more relaxed after 4 or 5 dives a weight check is in order for sure. On my first trip I did 9 dives. After 5 dives I was becoming more relaxed and comfortable and got rid of 4 pounds 20 down to 16 for the last 4 dives. The next trip after 4 or 5 dives I did another weight check and dropped another 2 pounds, down to 14 for the rest of that trip. I was using a new wetsuit and getting used to diving in saltwater. I think as your wetsuit gets broken in and you relax and breath normally instead of on the top 1/2 of your lungs you can drop weight. I haven't ever used anything but an AL80 so I am sure anything different would make for a change in weighting.

 

[Bubbletrubble]

Perhaps the BC inflator valve was leaking or got stuck open. It is not too uncommon with rental gear, which is one reason I ALWAYS bring my own gear. With rental stuff you have no idea how well it has been maintained. Even so, with a stuck inflator you should have been able to vent air faster than it filled the BC. I know you were scared, but did you hear any air rushing into the BC during the ascent?

No I bought all new gear. I wouldn't be comfortable in rental gear....to many bad things could happen

Oh and as someone else said, no more rental gear for me. I'm buying my zeagle zena before our next dive trip so I can become intimate with the set up!

I realize this is going off on a tangent...

A few of the participants in this thread have expressed a distrust of rental gear. Isn't testing out rental gear taught in OW classes? I recall my instructor showing us how to do a series of simple, quick checks.

Don't get me wrong. I would prefer to use my own gear because I'm familiar with its operation and I'm certain that it's been serviced/maintained properly. Nevertheless, I know that I can check whether rental gear is "fully operational" and safe to use.

How many newbies get their OW certification and are then compelled to rent scuba gear? I would guess most (myself included).
How many of those newbies pick up the rental gear (regs + BCD) and just assume that everything works without checking function in a systematic way? Sure, they'll catch a freeflowing reg as soon as they pressurize the system, but what about other, more insidious issues? Are they 100% certain that the over-pressure valve works properly on the BCD? Are they sure that the BCD can add, exhaust, and hold air properly?

Dive shops should be maintaining rental gear so that it is functional, but...let's be honest about it...the gear gets used and abused. Stuff breaks. It's up to the user to do the proper checks. If you don't know how to do these checks, learn how. You should be doing the same checks with the gear that you buy.

Be safe out there.

 

[Bossman]

Air can get trapped. You have to know when you add air to the wing, it will be there unless you dump it. I've had times that I add air at depth, and then when ascending I try to vent and nothing comes out. I usually roll slightly with my right shoulder up, then roll hard the other way with the left shoulder up, making sure the inflator is the highest point. Do it early when ascending, venting 10-15 feet before you think you need to. You can always add some again if you are sinking or having a hard time swimming up.

One of the main reasons many divers add a lot of air is that they are over weighted. More air added means more air to expand as you ascend, resulting in a larger buoyancy swing and less control if not vented properly.

Anytime I dive a new gear or tank config, I try to adjust based on my log book notes from previous dives. But it is still a good idea to grab a tank that is down to 500 psi and do a buoyancy check (empty BCD, float at eye level on a full breath, sink as you breathe out). You want the least amount of weight that still allows you to descend on the empty tank.

 

[TSandM]

And yes I always had trouble with buoyancy because I was dragging bottom while upright so I had to add air to the BCD to compensate.

Can you explain this a little better? When you say "upright", were you vertical in the water? Because if you are in that position, any kicking you do drives you straight up. This makes you have to dive negative, because if you are neutral, you will simply swim yourself up the water column. Thus, if you are in a vertical or 45 degree position, any time you stop swimming, it is highly likely that you will sink. This has nothing to do with proper weighting, but has a lot to do with the physics of swimming.