BC keeps filling up with water

[tracydr]

Thanks for all the responses. So it seems that pressing the purge button on the inflator hose when the BC is empty will cause water to flow in? That makes sense and I'm pretty sure that explains the constant filling up of my wife's BC.

We both try to weight ourselves such that we require no air in the BC during the dive. We might add some air at depth just to fine tune our buoyancy on the reef but we typically dump everything as we start making our ascent. I suspect this is where she basically just hold the button down too long in her effort to make sure that all the air is purged.

I'll mention to her to try use the kidney dump valve next time to see if that makes a difference.

Thanks again.

How do you compensate for the weight of air in your full tank if you don't need to add any air in your BC at the beginning of the dive?

 

[pasley]

I'll mention to her to try use the kidney dump valve next time to see if that makes a difference.

Thanks again.

It won't matter if she continutes to hold the dump open when there is no air commng out, then water will flow in. On todays dive, my BCD (DSS Backplate and wing to be precise) had zero water in it, my dive buddy (dive 6 of life time) had about a cup of water in hers.

It is possible that you are cutting it just a pound or two too close on the weights and she is having a little trouble getting down. If so then the addition of one or two pounds would help. I am not familiar with the water tempretutes in your part of the world or what type of exposure protection (wetsuit) you wear. From what I can see on the world sea temprature charts it looks like you range between a 7mm to a 5mm wetsuit. If so, there would be compression of the wetsuit the deeper you go and you would have to add some air as you decended. Not a full BCD of course but some to compensate for the compression of the BCD and the weight of the air in a full Alumimum tank (AL tanks being 4 pound positive at the end of the dive require 4 additional pounds of lead on the belt and so at the beginning of the dive you are technically 4 pound overweighted.) So if you are wearing a 5mm or thicker wetsuit and are diving with a BCD copletly empty of air at depth, your wife may be stuggling a tad bit to get down as at the surface she would be rather floaty, hence the need to purge every last atom of air out of the BCD.

As for the Air Siphon technique....hmmm, interesting. IMHO too complicated. Just as easy to learn to recognize when you need to dump air (a skill still required by the Air Siphon technique) and hold the hose all the way up and hit the purge valve. All you are really doing in this Air Siphon technique is holding the hose low (as most divers do) and holding the valve open and then when you get a bit floaty taking the J out of the hose and venting the air. In short it is just anouther way of doing it that really is not any different other than the need to wear your finger out holding a spring loaded button all the way up. But to each their own.

 

[Linedog]

A wise instructor once told me that water In your BCD=to little weight. Trying to descend, yet needing more weight. Boost her 2 pounds and see what happens.