Question regarding jacket BCD

[NewTODiver]

I'm still very new to diving. I recently went on a vacation and was diving with a rented Aqua Lung Wave BCD. On my second dive I added more weight because I thought the BCD was empty at depth since when I went to release air, nothing came out. I had to lower my lung volume to keep from rising too much. It turns out that I was properly weighted but I needed to get vertical to let the air out. In a horizontal position nothing would come out if I used the low pressure inflator.

Is this normal? I was certified using a mares jacket and never noticed this problem. It was a real pain every time I ascended a bit to have to get completely vertical just to release some air from the BCD. Is this just a cheap jacket?

Thanks.

 

[WileEDiver]

NewTODiver,

Many BCDs (both jacket and back inflate) have alternate pull dumps that allow venting of air from the BC while in a horizontal or head-down attitude.

I'm not personally familiar with the Aqua Lung Wave, but according to the specs on Aqua Lung's web site, the Wave has an 'Optional lower right side pull dump." Your dive operator may not have sprung for this option for their rental units.

When purchasing a BCD, you probably want to make sure that this alternate dump is installed (or at least available) on any model you are considering.

 

[waterwraith]

I had the same problem when I was doing my OW certification.
I finally tried the dump valves when horizontal and it worked beautifully. When using a jacket BC it is also helpful to squeeze with your elbows when pushing the deflate button.

 

[RICHinNC]

Not being sarcastic....but air floats in water....

no matter what you are wearing...bcd...dry suit..whatever...you have to get in a position that puts the valve you are venting from high. You may even have to dip one shoulder to get all the air out if you are settling down say to take a pic.

My bcd has a dump valve on each shoulder and one at the bottom so if i am in a normal verticle position i can dump from either the left or right side.....or if i am head down ....totally upside down....i can dump still. And that is actually something to think about when you buy your bcd....

it is trying to dump air when in the wrong attitude (position) that helps fill the bcd bladder with water.

 

[ScubaRon]

Neither in jackets, ADV or back-inflate BCs is it necessary to get completely vertical, Did you raise the inflator of the corrugated hose above the valve? If not, that may have been the issue.
Alternatively you can use the pull-dump that most BCs have by pulling on the inflator.

If this really bothers you Mares has several BC's (Morphos Twin, Dragonfly, HUB etc.) that have the AirTrim feature with dual valves. This opens up both valves and you don't have to worry about your position.
I haven't personally used it (still trying to find a Morphos Twin in my area...), but everyone who has used it seems to like the feature a lot.
ScubaRon

 

[NewTODiver]

Thanks for the replies. I will definitely look for a BCD which has a dump valve on the bottom/back of the jacket. I like to be upside down at times while taking a picture. Yes, I raised the inflator completely above me.

Part of my problem is probably due to my tendancy to swim slightly head down and fin up. I know this isn't considered perfect trim, but at least I know that my fins will never hit any coral, or silt the bottom in front of divers following me. Even though I still consider myself to be learning, I was proud that I never touched the bottom once except to rest on a finger while I took a photo. I was astounded while following the divemaster as I watched him kick his fins through sea fans as if they didn't matter. He shredded quite a few.

Once again, thanks.