Water in BCD

[pelagic_one]

Hi all, when my dive is finished, I find the BCD half full of water. How can I avoid this and also purge the water out while diving? 'Seems like I wouldn't have the rated lift capacity if the BCD is half full of water. Thanks!

 

[lizardland]

Hi all, when my dive is finished, I find the BCD half full of water. How can I avoid this and also purge the water out while diving? 'Seems like I wouldn't have the rated lift capacity if the BCD is half full of water. Thanks!

Most (all?) BCD's have a dump valve at the bottom of the bag. If you make this the lowest point (as you would be if bobbing on the surface) then when you add air and the BCD reached its max volume then it will force the excess water taking up space out of the dump valve. You may need to manually pull the cord depending on how stiff the spring is in it holding it closed. If it is a horseshoe type wing then you may need some underwater gymnastics to get the water to drain into the side of the wing that has the vent.

How you would actually purge it during a dive, I'm not sure. It's not something I've ever really tried or worried about. I don't really get that much in. Some but nowhere near half full. It sounds like you may be holding the dump button down too long when descending. I'd concentrate on that first. If you're needing a lot of BCD volume underwater then chances are you're overweighted or diving a very heavy rig.

 

[tursiops]

It sounds like you may be holding the dump button down too long when descending

THIS. Holding the inflator up over your head and holding down the dump button will let water in if no air is coming out, and not just when descending. Staying horizontal and using the hip dump works better underwater.

 

[boulderjohn]

Try to avoid putting it in there in the first place.

Water usually enters the BCD through frequent ineffective attempts to dump air. What causes that?

• Becoming neutrally buoyant requires some air in the BCD bladder, and that air volume will be affected by changes in pressure as you change depths. If you are properly weighted, the change in volume in the BCD will be minor, and you can compensate for most changes in buoyancy by your lung volume, meaning you will have little need to adjust the amount of air in the BCD during a normal dive. If you are overweighted, you will have a significantly greater volume of air, and that greater volume will have a greater impact on buoyancy. You will need to add or (especially) subtract air frequently, creating more opportunities for water to enter the BCD.
• Air wants to go up, so it will concentrate in the highest point of the BCD. If you need to dump air, that is where it needs to be dumped. If you try to dump air from a vent that is not the highest point, air will not come out efficiently (or at all), and water will come in.
• Many inexperienced divers dive with their bodies in a 45° posture, meaning the shoulders are the highest point. They will likely try to dump from the inflator hose. To make that work effectively, they need to make the body even more upright, and they need to hold the hose high, because, again, air wants to go up. Many inexperienced divers just swim along and press the inflator hose dump button without raising the inflator enough, and air will not come out.

Summary: Make sure you are properly weighted so that you need little air in the BCD to become neutrally buoyant. Swim in horizontal posture, with the BCD level. When you need to burp out a little air, lift your butt a fraction and pull on the rear dump. If you are properly weighted and feel the need to dump some air, a tiny pull will release a few bubbles, and that should be all you need. Many experienced divers only use the inflator hose to release air at the beginning of the dive, when they first descend.

 

[BoltSnap]

I find the BCD half full of water

In addition to what has been said above, if you really mean "half full of water" and that's what actually happens, that is WAY too much water under any circumstances. Something is wrong here. Having some water in there is normal, but "half full of water" indicates a more serious issue.

 

[noprowiththebow]

I had this issue, recently, with new gear. I finally figured out that I was either too buoyant or negative. Also, I was used to other gear and had to get used to the inflator position on my new gear. Good luck!