I think there are some problems with definitions here.
A "BC" is a device you wear that has a flotation bladder and allows you to compensate for the weight of the air you are going to breathe, and the loss of buoyancy from your exposure protection at depth. BCs come in several different designs -- Jacket BCs have an air bladder that wraps all the way around the diver, so when they are fully inflated, the diver feels a squeeze around his body, and tends to be held up in an upright position on the surface. Back inflate BCs have all the flotation behind the diver. They don't wrap, and don't squeeze. They tend to be less bulky in the front than jackets. Either kind of BC can be had with integrated weights or without them. A backplate and wing is a specific type of back-inflate BC, where the support for the tank is a metal or plastic plate, and there is a separate air bladder, or wing, that is attached to the plate, and a separate harness, that attaches the plate to the diver. This setup can also be assembled with an integrated weight system, although it commonly is not.
If all the weights that are required to sink one's exposure protection are attached to the BC, then you are quite right that anyone removing such a rig will then have to deal with the fact that the rig is now quite negative (since it's not balanced by the neoprene any more) and the diver is quite positive (because he has been deprived of the weight he needs to be neutral). This is one of the reasons that a lot of people prefer NOT to put all the weight on the rig. This can be accomplished by the use of a belt, or a weight harness like the DUI Weight & Trim. The latter leaves you with the possibility to pull weights, rather than drop a belt, but the weight harness is separate from the BC, so you can take the BC off without becoming too positive.
Does this help at all?
A "BC" is a device you wear that has a flotation bladder and allows you to compensate for the weight of the air you are going to breathe, and the loss of buoyancy from your exposure protection at depth. BCs come in several different designs -- Jacket BCs have an air bladder that wraps all the way around the diver, so when they are fully inflated, the diver feels a squeeze around his body, and tends to be held up in an upright position on the surface. Back inflate BCs have all the flotation behind the diver. They don't wrap, and don't squeeze. They tend to be less bulky in the front than jackets. Either kind of BC can be had with integrated weights or without them. A backplate and wing is a specific type of back-inflate BC, where the support for the tank is a metal or plastic plate, and there is a separate air bladder, or wing, that is attached to the plate, and a separate harness, that attaches the plate to the diver. This setup can also be assembled with an integrated weight system, although it commonly is not.
If all the weights that are required to sink one's exposure protection are attached to the BC, then you are quite right that anyone removing such a rig will then have to deal with the fact that the rig is now quite negative (since it's not balanced by the neoprene any more) and the diver is quite positive (because he has been deprived of the weight he needs to be neutral). This is one of the reasons that a lot of people prefer NOT to put all the weight on the rig. This can be accomplished by the use of a belt, or a weight harness like the DUI Weight & Trim. The latter leaves you with the possibility to pull weights, rather than drop a belt, but the weight harness is separate from the BC, so you can take the BC off without becoming too positive.
Does this help at all?
