BP/W...please explain what it is!

[cool_hardware52]

Correct me if I'm wrong here, Tobin, but since that the OP is diving in cool to cold water while wearing an exposure suit (wetsuit, drysuit), the wing should be able to lift the rig with a full tank of air and dive weight (backplate, backplate w/ bolted on weights, integrated weight pouches, weight belt, combination thereof) at the surface.

Proper ballast and wing capacity are not always the same thing.

Any BC needs to be able to do two things:

Float the diver's "rig" with a full tank, if they ditch it,

&

Be able to compensate for the maximum possible change in buoyancy of the diver's exposure suit.

Neither one of these requires the diver start the dive negative by the weight of their gas.

The absolute minimum ballast required is the equal to the buoyancy of the diver's exposure suit at their shallow stop depth with an empty tank.

If a diver chooses to mount all of their ballast to their rig, they will need a larger capacity BC than would be required if some of their ballast was on their person, i.e. weight belt.

For example:

Suit buoyancy = 18 lbs

80 cu ft tank (6 lbs of gas, in a non buoyant tank)

If all 18 lbs of ballast is on the rig it will be 18 + 6 = 24 lbs negative with a full tank, but the suit can only loose 18 lbs if fully compressed.

This will require a wing greater than 24 lbs.

OTOH, if the diver was using a 6 lbs weight belt, then their rig would be only 18 lbs negative with a full tank. A ~20 lbs wing is now sufficient.

20 > 18, easily float the rig with a full tank, and 20 > 18, easily compensates for a fully compressed wetsuit.

I am not a fan of mounting 100% of the required ballast to the rig for cold water single tank diving.

Tobin

 

[ivobj]

Hmmm...

Sop when you put an Oxycheq wing on a Dive-Rite Transplate, and mount them on a tank they turn into a Halcyon rig?

Must have been the blue tanks that did it!

 

[tflaris]

Old video.


YouTube - GUE Backplate how to

 

[Like-a-fish]

If you're wearing only a light skin, is that un-padded metal backplate comfortable
against your dorsal fin?? Looking at the photo i would think not...Would like to try it
though.
Could rig up a pad i suppose.

 

[Gombessa]

If you're wearing only a light skin, is that un-padded metal backplate comfortable
against your dorsal fin?? Looking at the photo i would think not...Would like to try it
though.
Could rig up a pad i suppose.

Whether dive skin or 7mm wetsuit, you never even notice the plate is there. It's actually quite comfortable.

 

[ligersandtions]

Whether dive skin or 7mm wetsuit, you never even notice the plate is there. It's actually quite comfortable.

The only time I notice my plate (and it's more the shoulder straps, which I'd have to deal with if I had a traditional BC) is on the surface. Underwater, everything just kind of disappears.

 

[Like-a-fish]

Good to know it's comfortable- thanks, Gombessa.

 

[CompuDude]

Good to know it's comfortable- thanks, Gombessa.

I would not be overly fond of hiking long distances with a bp/w with hog straps, wearing only a t-shirt underneath.

For regular diving (that doesn't require long hikes), whether your exposure protection is a t-shirt or a drysuit with thick undergarments, the backplate is not hurtful to your back in any way. Not even a little that's no big deal, it's simply not painful.

Well, maybe if you left your backplate sitting out in a direct, very intense sun for a couple hours and put it on immediately onto bare skin or a very thin dive skin. Then maybe it would be hot.

But it turns out smooth metal on your back isn't painful. Lean up against your car sometime and ask yourself if it hurts.

 

[Gombessa]

But it turns out smooth metal on your back isn't painful. Lean up against your car sometime and ask yourself if it hurts.

Most people I've talked to actually worry about the wingnuts digging into their spine (which, btw, also doesn't happen, the plate's channel is recessed far enough for them to not even be close).

 

[AndrewST]

I am not a fan of mounting 100% of the required ballast to the rig for cold water single tank diving.

Tobin

How come? What is the disadvantage of having all your weight, including dump-able on the Rig and only one tank?