Choosing Your First BCD

A BCD's job is simple to describe and easy to get wrong when shopping for your first one: hold you neutrally buoyant at any depth, and let you adjust that buoyancy quickly and predictably. Beyond that, the two most common styles trade off differently.

Jacket-style BCDs wrap air around your sides and back, which makes them forgiving and stable at the surface -- a common recommendation for new divers who are still building trim and finning technique. Back-inflate designs concentrate the air bladder behind you, which tends to give a more horizontal, streamlined position in the water once you're used to it, at the cost of being slightly less self-correcting at the surface.

Lift capacity matters more than most first-time buyers expect. You need enough lift to comfortably offset your heaviest realistic setup -- steel tank, thick exposure suit, weights -- not just what you're diving in warm water with a 3mm wetsuit. If you expect to dive both warm and cold water over the life of the BCD, size for the cold-water setup; you can always dive an oversized BCD mostly deflated, but you can't add lift a smaller one doesn't have.

Fit matters as much as lift. A BCD that rides up, shifts your tank, or digs into your ribs will not get more comfortable with a longer dive -- try it on with the actual tank and weighting you plan to use before you're relying on it forty feet down.