Another BP/W Thread...

[dmaziuk]

Not heavier: less volume for the same mass. My wife's jacket is actually heavier than my rig.

 

[Dan]

I’ve been thinking about this type of BCD. I can imagine that you’ll have a good trim (prefectly horizontal underwater) with BP/W. But I don’t like to be in this position all the time since I don’t dive in cave. It’s like walking and looking up to the sky. Once in a while I like to rest my neck & swim in angle or even in vertical position. Jacket BCD allows me to do that.

This situation brings me to a question about floating on the surface, which sometimes I do while waiting for skiff to pick us up. With jacket BCD, I can just put a bit of air in BCD and float vertically, may be even do a short power napping, without finning. Can I do that with BP/W?

Another thought comes to mind, if I were to pass out at the surface, would the back inflate force my face down to the water & drown?

 

[tbone1004]

@Dan_T you can sit in whatever trim you want in whatever bc you have, it's all about body position to change your center of buoyancy and gravity by moving your legs in and out. You want to go vertical? let your knees drop a bit and extend your legs. Want to go back to flat? arch your back and pull your knees up *skydiver position*

On the surface, I can lay on my back and make like an otter with no issues at all and I never fin while on the surface unless I am trying to move anywhere. I can go anywhere from on my face to on my back and stay there, again all about body positioning

You shouldn't be passing out on the surface, but there is no guarantee any BC is going to keep you on your back, including jackets. It all depends on how much gas is in them and where your lead is. If you have 20lbs of lead on the front side of your body, you're going to be face down regardless of the BC. If you have 20lbs behind you, you're going to struggle to lay on your stomach

 

[2airishuman]

I’ve been thinking about this type of BCD. I can imagine that you’ll have a good trim (prefectly horizontal underwater) with BP/W. But I don’t like to be in this position all the time since I don’t dive in cave. It’s like walking and looking up to the sky. Once in a while I like to rest my neck & swim in angle or even in vertical position. Jacket BCD allows me to do that.

Whatever works for you.

The idea with a wing is that it puts the buoyancy around your cylinder(s). The gas is, after all, the main thing you're compensating for with a buoyancy compensator (the other being wetsuit compression). If you are deep and in two piece 7mm well yes any BC will put the buoyancy in the wrong place to some degree.

I find that I can achieve any orientation I want underwater with a BP/W. I haven't used jacket BCs or back-inflate BCs enough to make a comparison.

This situation brings me to a question about floating on the surface, which sometimes I do while waiting for skiff to pick us up. With jacket BCD, I can just put a bit of air in BCD and float vertically, may be even do a short power napping, without finning. Can I do that with BP/W?

It depends on the situation. If you are diving a single aluminum cylinder, in the ocean, and are on the surface at the end of your dive with 500 PSI left, there is going to be a distinct face-forward tendency with a BP/W that you're going to have to deal with. It's not insurmountable. You just have to learn to lay back and get the wing under you. But I don't think there's any question that a jacket BC is better in this situation, because some of the buoyancy is at your sides.

Now, if you're in steel doubles, in freshwater, at the end of a rule-of-thirds dive so you have 1200 PSI left or whatever, well, then you can float vertically. This is why all the cave dwellers will tell you there is no face-forward tendency with BP/Ws.

Another thought comes to mind, if I were to pass out at the surface, would the back inflate force my face down to the water & drown?

If you pass out at the surface, you have already lost the plot.

 

[tbone1004]

@2airishuman I can sit with completely dead singles with no problems at all, but when I have to wear lead, I don't put it up front and try to keep it just behind or at my sides. Obviously if you blow the thing all the way up it can try to push you forward, but most of it is an imbalance of lift/ballast where the lift is concentrated out back and the ballast out front and that causes the extreme tip. All back inflates are prone to it if you put the lead in the wrong spot

 

[2airishuman]

@2airishuman I can sit with completely dead singles with no problems at all, but when I have to wear lead, I don't put it up front and try to keep it just behind or at my sides. Obviously if you blow the thing all the way up it can try to push you forward, but most of it is an imbalance of lift/ballast where the lift is concentrated out back and the ballast out front and that causes the extreme tip. All back inflates are prone to it if you put the lead in the wrong spot

The point is that with a BP/W you have to do it right and it is situational.

With a good quality jacket BC it doesn't matter. They will float you vertical regardless.

Don't get me wrong, I love my BP/W and won't dive anything else. Their drawbacks can be managed. They are still drawbacks, however.

 

[Dan]

Whatever works for you.

The idea with a wing is that it puts the buoyancy around your cylinder(s)...It depends on the situation. If you are diving a single aluminum cylinder, in the ocean, and are on the surface at the end of your dive with 500 PSI left, there is going to be a distinct face-forward tendency with a BP/W that you're going to have to deal with. It's not insurmountable. You just have to learn to lay back and get the wing under you. But I don't think there's any question that a jacket BC is better in this situation, because some of the buoyancy is at your sides,,.

I dive NDL in warm water with single AL80, 12lb lead & 3mm wetsuit. I put 4 lb lead in each side of waist integrated pouches & 2lb lead on each of my shoulder blade pouches. Also lower my AL80 tank so that the upper cam band strapped around the tangent line (where the cylinder shape meet the half dome) of the tank. With that configuration, at 500-1500 psig left in the tank & a tiny puff of air in the BCD I can vertically float with face up without moving a muscle, like a life jacket would do to you.

 

[Dave Bevan]

I'm a new OW Certified diver and would like to get some gear. From the general consensus on here BP/W is the ideal go to BCD. I plan on diving tropical where a 3mm will be the max Wetsuit I'd wear and plan on diving single Aluminum tanks. But I would like to get into technical dives in the future.

The brands that keep popping up is Dive Rite, Deep Sea Supply, and Halcyon. Any other recommendations? I'm going to go more towards a SS plate since I was using 8lbs in a Hydros Pro during my certification dives.

The argument for BP/W is pretty much over if you are interested in progressing to technical diving. Not really worth buying twice and having a bp/W from the start will help you feel more comfortable when you do progress onto one.

I am a halcyon reseller so I will elect to avoid recommending a brand for you. Just ensure you take a good look at the quality of the rig. Particularly the wing.

Avoid buying all the bells and whistles if you are on a budget a simple one piece harness/No adjustment/No padding will suffice to begin with.

Steel is great if you don't travel by air a lot. But even if you do it can still be a good option. By single tank gear weights in at 14kg even with a steel bp.

Have fun.

 

[dmaziuk]

Another thought comes to mind, if I were to pass out at the surface, would the back inflate force my face down to the water & drown?

If your dive plan is to pass out on the surface, you want a horse collar BCD for yourself and a couple of rescue certs for your buddy.

 

[Dan]

If your dive plan is to pass out on the surface, you want a horse collar BCD for yourself and a couple of rescue certs for your buddy.

I have no such dive plan. Just thinking of what if situation. It could happen when a diver get hypoxia, heart attack or panic & shot up to the surface, etc.