BP/W for a totally newbie diver?

[James79]

Is there a jacket BCD that you can dive doubles with?

P.S.: I was not suggesting that diving single tank with a doubles wing was a good idea.

I have heard of jackets that were made for either, and from what was said they did it poorly (too much plastic being relied on for the weight of doubles).
And I wasn't trying to imply that anyone thought single tank with a doubles wing was a good idea... just trying to be as precise in my explanation as I could for anyone else reading (with or without a baseline of knowledge on it). Sorry if I came across wrong on that.
Respectfully,

James

 

[David Novo]

I have heard of jackets that were made for either, and from what was said they did it poorly (too much plastic being relied on for the weight of doubles).
And I wasn't trying to imply that anyone thought single tank with a doubles wing was a good idea... just trying to be as precise in my explanation as I could for anyone else reading (with or without a baseline of knowledge on it). Sorry if I came across wrong on that.
Respectfully,

James

I have heard of back-inflate BCDs that, as you mentioned, "were made for either, and from what was said they did it poorly".
My point was to try to understand if there was a "jack of all trades" BCD that performed better than a "jack of all trades" BPW. I consider both of them sub-optimal options but I understand that there is a compromise between financial investment and optimization.

 

[KenGordon]

Diving single tank with a BCD that is good enough for twins is not the same as with a BPW with a doubles wing?

No.

I have been diving a 20kg doubles wing with a 15 and pony for the last few weeks. I have left the 8kg warm water wing in the car as my biggest concern is having to float for a long time waiting to be found.

The main problem is that the positioning of the hip dump is much higher (imagining a horizontal diver) than it would be on a twinset as the wing wraps around the CYLINDER. This means you have to stretch further and more gas is above the valve and hard to get rid of. A BCD wraps around the DIVER so the various dumps etc remain in the same place. In a BCD the lift mostly depends on the size of the diver, not the size of the cylinder.

Diving an overly large wing is quite nasty. Of course diving too big a BCD is nasty, but once it fits it fits and you don’t need to have several. Again, my point is not which is superior, just that some of the claims for BPW are bogus.

Round here there are plenty of people that dive a single all year but occasionally do stuff that needs a twinset. They can manage with the better BCDs but would badly compromise their diving if using a twinset wing all year.

 

[MichaelMc]

To be clear, I was not suggesting that a BP/W with a specific wing and plate is flexible to all dive situations. But if you wanted to change one part of a BP/W, you can do that without searching and hoping someone makes a complete BC with all the things you liked about your current BC but with the one change you wanted to make. Understanding that the wing is a big part/component that is expensive and likely impractical to customize internally once you’ve picked it, you would need to buy a new wing.

(Thou some small doubles wings may be serviceable but not near optimal for both singles and modest doubles, e.g., DivRite Rec wing, though not really recommended for singles. And when I was researching small doubles, some singles wings were recommended as compatible, some of the less tailored ones in shape. So one wing can cover a wide range.)

The easy and more frequent use of flexibility is what you put where on it. Particularly trim weights can be put on any of the straps or even the plate top edge. That is not as easy, in a clean and tidy manner, with most sewn together BCs that I have seen.
ETA: The buddy commando does not look any different from other sewn together BCs in this respect.

 

[KenGordon]

So where is a good starting point for lift?

I'm 5'10" and 200#. I'l be diving both sides of Mexico, mostly Sea of Cortez. Single alu tank.

You need enough lift to support your kit if you take it off at the surface. That can be a lot for something like a heavy twinset. This is important if you are taking the kit off to get into a boat. The other factor is enough to make up for loss of buoyancy in a wet suit which is compressed at depth. So if you are a large person in a thick suit this will be more than a small person in a thin suit or swimming costume.

Then you need a bit for the change in buoyancy of the cylinder due to gas used.that isn’t much usually.

With a drysuit or a thin wetsuit you should never have much more than a couple of kilos lift in the wing if properly weighted. I am not sure that the shape of the bladder is so important in that case.

 

[KenGordon]

I have heard of back-inflate BCDs that, as you mentioned, "were made for either, and from what was said they did it poorly".
My point was to try to understand if there was a "jack of all trades" BCD that performed better than a "jack of all trades" BPW. I consider both of them sub-optimal options but I understand that there is a compromise between financial investment and optimization.

Back inflate is orthogonal to taking a twinset. For marketing reasons are many back inflate BCDs now, there are not so many BCDs that take a twinset. There might be the odd one that does both, like the AP Tekwing, but I don’t think that is good for a single.