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

[RJP]

This is the backplate

This is a wing

This is how they look together on a tank

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!

 

[simmonsjr]

This isn't true in general. I know my back-inflate BCD is relatively modular, not quite to the point of BP/W since the "Harness" and "backplate" equivalents are stuck together, however the wing, tank-bands, most of the straps and everything are modular. For now I like all the "bells and whistles" (integrated weight system, pockets, etc., but I think if I ever get into more technical stuff, I can probably use the same wing I have now and just buy a backplate system. It can also take doubles if I go that route at some point.

Zeagle has somewhat blurred the line between the two since their high end BCDs have a lot of BP/W features, although for a minimalist there is still too many extras I'm sure.

I think that you mean "this is true in general; however. . .." I will grant that you can do more with a Zeagle BCD than you can with most; however, I do have to point out that there is quite a bit of difference difference between being able to switch out some components and a truly modular design.

Also while some traditional BCDs claim that you can use them with doubles the results of doing so with most (if not all) of them leave much to be desired. Most individuals in my experience end up trying do do it a couple of times and then quickly giving up and getting a BP/W instead.

 

[FredT]

Plates and wings are modular, so you can adjust the system to fit you diving conditions and style.

While the "standard" plates fit a bit over half of the divers well, short waisted and long waisted divers will find a rig that fits them to be much more comfortable. I have made plates from over 24" long to under 10" for specific divers, in weights from 1 pound to over 30 pounds negative buoyancy.

the other side of the BP/W story is reduced air consumption. As you increase the streamlining and reduce the drag of you rig, your air consumption goes down considerably, this is magnified by the improvement in your trim where you get to swim with minimal projected area into the current.

when conditions change you can simply change the one part of your rig that doesn't fit the new situation instead of buying a whole new rig.

 

[AndrewST]

So with everything I have gathered from this thread, it seems like I could easily get a 6-10lb stainless Back Plate, add a couple dump-able weight pockets to the waistband strap, and be good on the weight and not have to screw with a weight belt. Sounds nice...next question. How much lift should I go for in a wing? I have seen wings with 20lbs of lift up to what appeared to be 77lbs? How do I calculate how much lift I would need?

 

[Coldwater_Canuck]

I think that you mean "this is true in general; however. . .." I will grant that you can do more with a Zeagle BCD than you can with most; however, I do have to point out that there is quite a bit of difference difference between being able to switch out some components and a truly modular design.

Just pointing out that it wasn't the true differntiator since BCDs don't necessarily need to be "one-piece", however, it's not important, just a matter of semantics.

Also while some traditional BCDs claim that you can use them with doubles the results of doing so with most (if not all) of them leave much to be desired. Most individuals in my experience end up trying do do it a couple of times and then quickly giving up and getting a BP/W instead.

[/quote]
What is the major problem you see?

 

[FredT]

So with everything I have gathered from this thread, it seems like I could easily get a 6-10lb stainless Back Plate, add a couple dump-able weight pockets to the waistband strap, and be good on the weight and not have to screw with a weight belt. Sounds nice...next question. How much lift should I go for in a wing? I have seen wings with 20lbs of lift up to what appeared to be 77lbs? How do I calculate how much lift I would need?

How much air will you carry, and what suit compression issues are there in your diving style? Also the assumption is that you have a balanced and properly trimmed rig so no weight belt is needed to start with JUST YOU, and no exposure suit

The wing HAS to lift the disposable air in your rig at the start of the dive, PLUS any suit compression buoyancy loss experienced during decent.

The first is about 6 lbs with a single 80, but could be up to 40 or more pounds with large doubles and stages. Suit compression is a function of water temperature, depth and suit type.

Single tank warm water with a 2/3mil suit an 18 to 24 pound wing would work as a minimum. I use a 40 pounder in similar situations due to spearfishing considerations.
Shoot me an e-mail and I'll send you the ballasting/buoyancy calculation instructions sheet.

 

[ligersandtions]

So with everything I have gathered from this thread, it seems like I could easily get a 6-10lb stainless Back Plate, add a couple dump-able weight pockets to the waistband strap, and be good on the weight and not have to screw with a weight belt. Sounds nice...next question. How much lift should I go for in a wing? I have seen wings with 20lbs of lift up to what appeared to be 77lbs? How do I calculate how much lift I would need?

If you contact Tobin at DSS (cool_hardware52 on here), he can get you set up with the perfect gear. However, I do have to warn you of one thing - make sure you know what kind of diving you plan to be doing in the near future. When I bought my bp/w, I was diving a 7mm wetsuit and an Al80. I now dive a drysuit and an HP130 - my wing is not sufficient to float my rig, so tossing it in the water and donning there is not an option for me.

Tobin's customer service is top notch....his gear is too

 

[AndrewST]

I am a Diver in the Northwest, so cool - cold water diving, 3m wetsuit in summer up through a dry suit in winter. Single tank, an 80al maybe a HP Steel tank. Both Fresh and Cold water diving. FredT, message sent.

 

[cool_hardware52]

How much air will you carry, and what suit compression issues are there in your diving style? Also the assumption is that you have a balanced and properly trimmed rig so no weight belt is needed to start with JUST YOU, and no exposure suit

The wing HAS to lift the disposable air in your rig at the start of the dive, PLUS any suit compression buoyancy loss experienced during decent.

Not always. For example a diver using a wetsuit that's ~20 lbs positive at the surface and a 80 cu ft cylinder.

He has at most 6 lbs of gas, and his suit will easily loose 6 lbs of buoyancy from the surface to 15 ft. 1 ata (surface) to ~1.5 ata will compress a wetsuit quite a bit.

The absolute minimum ballast required is the amount necessary to hold a shallow stop with a near empty tank.


Tobin

 

[fnfalman]

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.

I believe that when you and I spoke at the SCUBA show, we calculated out my wing lift requirement to about 27-lbs:

Faber M-series 120cuft tank = -15.58lbs full
Valve = -2.00lbs (approximate)
Regulator = -2.00lbs (approximate)
stainless steel backplate = -6.00lbs
Dive comp/compass/knife/light = -2.00lbs (approximate)

The 7mm wetsuit will float me and the negative buoyancy total dive weight compensates for the positive buoyancy characteristic of the heavy wetsuit.

With the above rig, I'm properly weighted and can hold a safety stop with zero air in the wing and control the buoyancy by my lungs.

So, the wing that I would need is around 27lbs lift. But I prefer to err a hair to the side of caution and went with a 30lbs wing. It lifted me and the rig just fine in the ocean at the beginning of the dive while the tank is still full of air. By the end of the dive, I'm now about 9lbs lighter due to the consumed air, so at the end of the dive there is a surplus of lift by around 9-10lbs depending on how much air remains in the tank.