Frustrated with back-inflation BCDs...

[wra]

My buddy and I lost our dive gear to the airline a few years ago and were treated to new equipment. The only choice anymore are back inflation, weight integrated BCs.

I've done about 25+ dives with the new BC and my buddy about 15 dives. We both would rather have our old BCs back.

Neutral bouyancy with a full wet suit (7mm for me and a semi-dry for her) at anything less than 20 feet is now a struggle. And the shoulder dump valves have moved higher, so we have to go vertical to dump air, rather than remain horizontal.

We both are rescue certified with >100 dives each, and have been diving for over 10 years (there's a few year hiatus in there for kids). Are we the only ones to lament the changes? Anyone else out there feel like BC manufacturers still just don't get it???

 

[JohnStrr]

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[Gilligan]

I'm not sure what dive shops you are checking BCD's at but back inflate BCD's are not in the majority by the brand name manufacturers such as Oceanic, SeaQuest, Sherwood etc. These companies usually make one, maybe two, back inflate BCD models. The rest of their models are not. As for weight integration, it appears the industry has moved in that direction, but again, most companies still make at least one model that is not weight integrated. :shades:

 

[Cave Diver]

There should be no problem finding a traditional jacket bc if that is what you are looking for.

Regarding your problem staying neutral @ 20', I am assuming that you are having a problem staying down.

Some back inflates may trap air. A lot of that depends on the size and design of the wing. If it is a large wing there may be more of a tendency to trap air since there is more room for it to "shift."

Don't forget that their should be rear dumps also, and a slight head down attitude should allow you to dump from there. That may solve the "get vertical to dump from the shoulder problem."

A lof of wings also seem to have too long of an inflator hose, which makes it more difficult to dump using that method.

Overall, I have found that back inflate is much easier to dive with, especially once you have the appropriate wing for your gear.

You didnt mention what brand BC, or whether the wing is replaceable or not, but there are several companies that make small wings for single tank recreational diving.

 

[herman]

I have dove both and I really don't understand your problems. My back inflates(2) and my jacket (and my wife's for that matter) have the shoulder dumps in almost the same place. In any event, the end of the inlfator hose is still where it's always been. There is no need to go vertical to vent any BC I have seen, just a simple lifting of the left shoulder.
As to finding a similar BC to your old one, Gilligan has it correct. There are many models that are jacket type with no weight intergration, in any case, you can just opt not to use it and strap on a weight belt. If all else fails, I bet there is someone on Ebay, or here that has one of your original BCs for sale.

Neutral bouyancy has nothing to do with BC configuration be it jacket, back inflate or BP/wing. If all negative bouyancy is equal to all positive bouyancy you are neutral. Now trim and proper weighting are a totally another matter. No doubt that being overweighted or under weighted can cause bouyancy problems but the style of BC has no impact on that.

 

[CobaltWave]

I have the SeaQuest Balanace back inflate with the intergrated weight system. I really like the weight system, but the back inflate is a challenge.

It seems that the shoulder dump valves have moved higher or better stated it has moved slightly down the shoulder in front of the BC. Which depending on how much air is in your BC moves the vavle below the water line making you either pop up you left shoulder ridiculously high or rotate a bit to the left a bit and fumble for your rear dump, in either case your trim is going to end up whacked and more than likely so will your bouyancy. Its kinda of difficult to judge how much air is coming out you rear dump.

Until I get the hang of the trick of the back inflate, I have come up with a simple solution, add about 2 - 4lbs of weight. I know its bad to add weight, but in doing so the BC requires more air, which inturn becomes easier to release from a horizontal position.

Once I get better at the rear dump method I'll drop the weight back down.

Good Luck

 

[wra]

We have the SeaQuests, too. I have the Balance, my wife has the Diva.

The back valve is hard to use as it's really an emergency dump. I tried just cracking it but it dumps too much air.

Once under 30 feet or so, there's little fiddling with the BC. I shoot video underwater and am able to manage bouyancy (up a little, down a little) with my lungs. Above 20 feet, the bouyancy is trickier. Perhaps cause we need to overweight to get under when the suits are dry at the beginning of the day. The semi-dry is prone to this problem.

Even to "pop" the shoulder valve with the inflator now requires we go out of horizontal. That's where the air has to be for the dump to work (either with the shoulder valve or with the inflator). Our old BC's had the valves more on the shoulder blade, rather than the shoulder. Maybe it's just that when these different BCs have air, the valve is in different places. The valve moves on the back inflate BC more than on the jacket.

We're experimenting with more weight. I've went up about 4lbs on our recent trip to Cozumel, adjusting for the microprene and hooded vest. I think CobaltWave is onto something there.

I appreciate all the thoughts. We really want to figure out the new gear.

 

[CobaltWave]

I guess we should actually be happy that were having this kind of problem with our back inflates. It seems to me that were actually weighted just about right for our gear, which makes use use very little air in our bcs. I mean if we had too much weight the bc would be full of air an it would be pretty easy to vent. I think the resolution to this problem might not be adding more weight but maybe to redistribute it better.

I'm planning on diving tomorrow and I'm going to try and put less weight in the trim pockets and more wieght in the side dump pouches. In doing this I expect to have the air in the bc reside closer to my shoulders to because of the slight weight difference pulling my waist down. With more weight in the trim pockets it make it easier for you stay topside, but below I think it tends to drop your shoulders a bit causing the air in the bc to move to the rear of it.

After diving with my back inflate, I now wish I would have went with either the Transpac II or just BP \ Wing set up. It seems to me the BCs like the Balance are a hi-bred between the tradition jacket and the BP\Wing. Designed to get people who like the idea of Wings but the familiar assurances of the jacket.

Good Luck

 

[Dyno Bill]

I have 2 SP jacket style BC's and a Dacor Rig which is a rear flotation BC. I havnt had any problems with any one of them. I like the Rig a lot more due to how secure it holds my tank in place and haw easily it is put on or removed. I think you might not realize the relationship or position of the dump valves themselfs in your diving attitude in the water. I'm probably doing a poor job of conveying a thought but if you could see your own position while traveling it might not be exactly as prone as you imagine putting the dump in a little different attitude. I hope you can desipher my attempt at drawing a picture with words.
Bill

 

[Bob]

I've never had to go vertical to vent air. I use the rear dumps on my Ranger, just a little "Burp" and I'm good to go. I do assend vertically, this is the only time during a dive that the shoulder dump is used. My personal experience is that carring extra weight will make your bouyancy harder to control rather than easier. :tree: Bob