What is the difference between a rear inflation BC and a BP/W setup?

[simmonsjr]

At the risk of being labeled a I just have to ask. Exactly how much difference is there between a rear inflation BC and a back plate with wings? The two seem rather similar to my, admittedly, inexperienced eye. Thanks.

Jason

 

[SteveAD]

A BP/W is a type of rear inflate BC. The main difference is that most "regular" BCs are essentially one piece units with fit and function capabilities defined when they leave the factory, and BP/w are 3 piece modular units (harness, plate, and wing) which can be mixed and matched to put together different ideal units for different conditions.

 

[piikki]

I am sure you already know that the biggest difference to the eye lies with the fact that BP/W has a hard plate whereas back inflate usually refers to either a one piece jacket BC-style or a unit like BP/W where instead of plate the wing attaches to a soft harness. (Actually BP/W is just one form of back inflate but for your questions sake, let’s call the other two BI to keep it simple.) Another immediately obvious difference is that BI:s often come with not only some padding but jacket BC-style accessories, like weight pockets.

Some of this usually leads to immediate conclusions with new divers (did with me). Metal plate looks uncomfortable and soft harness/vest looks more comfy. The truth actually is that for most people BP snugs the tank/rig way closer to the body and is surprisingly more comfortable, especially in water, than a soft pack that looks and feels very comfy above water. Pockets and all kinds of attachment points also look very useful. They are totally missing from basic (hog) BP/W. It can be hard to figure out which ones actually are useful as only in water will one know which things one can utilize. Pockets and attachment points can be added to BP/W harness/webbing too which is something that does not seem immediately obvious, and maybe make the rig look quiet unappealing. Even quick release weight pockets are available.

One great bonus with BP is that by using steel BP diver can distribute some extra weight evenly on the back of the diver. This is both a balance issue but even better, one can reduce the amount of lead one needs to carry. On the other hand, the more comfy padding a BI has the more it needs to be counteracted with extra weight.

Depending on the unit and fit they can both dive really well. With jacket style BI fit/size is most crucial whereas with BP one size pretty much fits all (some companies offer different size plates). A lot of people would never dive anything but BP/W but there are a lot who find it a bit hard core, and prefer at least a few quick harness releases etc that are common in the BI units. (Nobody says one can not go for a compromise and get BP and so called comfort harnesses too – that is I am too much interpreting as if all BP users are using continuous one-piece webbing for their harness).

Some people say that BP/W is more modular and that is a bonus. I think that is only true when compared to one-piece BI:s. There are also modular BI:s (made, for example, by Dive Rite and Oxycheq). However, it is true that BP/W has way more potential to grow with you as you can upgrade it to work with different kinds of diving by swapping just wings. There are some people who use soft packs when diving doubles but I think that is quite a minority. One great thing about modularity vs one-piece is that if you trash one piece you do not need to buy everything new.

I am sure someone will come with a more concise summary about the differences. For me personally BI (soft pack plus wing) originally looked way more appealing and comfortable. However in water it was way more sloppy, shifting around. I also felt very crowded on the front. I use/d same wing with both soft pack and BP but when I moved to BP I never went back, the whole unit just felt like part of me. I moved into one-piece webbing for harness and it was such a feeling of freedom when the whole chest area opened up (I still used weight pockets on the webbing on the waist to start with).

If you were asking if there is a basic difference diving back inflate and BP as to the way the inflation (on the back) and the wings function, the answer is no. Different brands of course will be different but my answer already had the clue – you can interchange wings between BP:s and BI systems, with the exception of built-in jacket style BI:s of course.

 

[fnfalman]

Very basic info on the difference between a back inflate and a BPW:

1. The back inflate looks like a jacket/vest while the BPW has harness.
2. The back inflate has built-in pockets while the BPW's pockets are optional.
3. The back inflate has a built-in air bladder while the BPW's air bladder (aka wing) is modular and interchangeable.

The BPW configuration is versatile because of its modularity. You can rig that mutha up as complicated as you want (depending on how fancy the dive you're about to do) or as simple as you want.

I personally don't see my needs for large pockets therefore on my BPW I only have one small cargo pocket. If need be, safety sausage w/whistle (not the same as SMB) can be clipped to one of the D-rings. My light is on a lanyard that is clipped to the shoulder D-ring and the light tucked into the belt. Slate? Strapped to the forearm or clipped to D-ring if needed.

But if I were to do some treasure hunting or intending on bringing shells back, I'd mount a couple of bigger pouches on. Or carry a net bag and clip it to the hip D-ring.

To each his own, but I do not care for the jacket/cumberbund wraparound feeling of either the jacket style BC or the back inflate BC. Not to mention chicks dig my rig because they think that I'm a badass tech diver.

 

[ZzzKing]

They are leaving out the most important thing. If you use one of them you will DIE!. Now if I just can just remember which one...

 

[Eric Sedletzky]

Not to mention chicks dig my rig because they think that I'm a badass tech diver.

Hey, if you're getting the chicks that's all that really matters at the end of the day, or dive?

 

[Colliam7]

Exactly how much difference is there between a rear inflation BC and a back plate with wings? The two seem rather similar to my, admittedly, inexperienced eye.

In the position of the wing (and center of lift), they are rather similar, as you already note. The primary differences from my perspective are: 1) greater modularity (already noted) of the BP/W, or at least 'easier' modularity; 2) greater a) adjustability and b) universality of fit (already noted) of the BP/W, at least wth a one piece harness - the position of D-rings, for example, can be easily adjusted with a one piece harness, whereas they are frequently sewn into position on non-BP BCDs; 3) inherent buoyancy characteristics; and 4) trim characteristics (associated with the weight placement of the BP, already noted). Most non-BP BCDs are positively buoyant, and add to the diver's weight requirement to offset that buoyancy. With a stainless steel backplate and wing, you generally have a negatively, or at most neutrally, buoyant unit. Yes, you have added weight in the BP - but that is weight shifted from the belt or pouches, and the added weight of the SS BP, for example, is usually less than the additional weight that is carried to offset the buoyancy of a non-BP unit. In fact, the shift of weight (of the BP, and possibly of a metal STA) to the (upper) torso affects trim, in a positive way. With a non-BP back-inflate unit, apart from the weight of the tank and regulator - which should be equivalent with both units - weight is concentrated at the waist (with a belt) or a little higher, in weight pockets with the weight intergated units. With the shift of weight toward the head, many divers (but not all) may find it a little easier to maintain good horizontal position underwater.

There may be, as several have noted, other subtle differences in features - for example differences in padding, or availability of pockets. But, most padding is unecessary to begin with, and pockets can be added to the waist strap of the BP harness, or attached to the exposure suit (dry or wet), so I view those more as variations on a theme, than as differences.

 

[dstrout]

Let me toss in a thought or two, one newbie to another. (Just passed my cert dive today). I'll skip the technical arguments & just give my personal impressions.

I got the pleasure to use all three BCD types. The BP/W was the most comfortable of the three. The BI wasn't bad, and the wrap-around I didn't like. Too much squeeze on the wrap-around. The BI was nice & I was happy with it until I tried the BP/W. Now it also feels constricting, though not as bad as the wrap-around. Mostly because of the cumberbund, but also all the "junk" (pockets etc) around your sides. Integrated weights are supposed to be more comfortable, but the BP/W + weight belt felt the most free to me.

My first time with the BP/W felt very wierd out of the water, almost like it was going to fall off or something was missing. As soon as you got in, it was awesome - I quickly forgot it was there at all.

I got a good deal on a Zeagle Ranger (BI) so I bought that before I got to try the BP/W in class. It's a nice BCD - I really like it. But I'm now shopping for a BP/W and will prob sell my Ranger when I find a good BP/W.

I can see it would take a few dives to get the BP/W just the way you want it. The inflator tube was never handy I always had to look for it. I'm sure that's just a matter of setup. The shoulder straps were a bit of a PITA to adjust, but that wouldn't be a be a big deal if you weren't sharing.

Overall, my advice is rent one of each & play with it, even if it's just in a pool session. I wish I had done that before I bought my BI, but for what I paid, I'll get out w/o a loss, so I guess it's no big deal.

Good luck!

dave.

 

[I Dive]

They are leaving out the most important thing. If you use one of them you will DIE!. Now if I just can just remember which one...

I use a jacket style, so I guess you are saying the BP/W will kill me if use it. Thanks for the advice, I will avoid the BP/W now in order to stay alive.

 

[simmonsjr]

Thanks to all for all of the insightful comments. Here's another question. I have some pretty significant shoulder impingement issues (especially in my left shoulder) as a result of injuries sustained during my time in the military. I've heard several people mention the need to chickenwing in-order to don or doff a harness. I think that might pose a pretty substantial obstacle for me. Would it be better to go with a BI until I can rehab my shoulders? (I've been working on that for two years, and I still have a long way to go.) Thanks.

Jason