Three main types of buoyancy compensators (BCs) are which of the following?

• A. BCs
• B. PFDs
• C. Regulators
• D. Wetsuits

Answer: (A)

Understanding how buoyancy is controlled underwater and what a buoyancy compensator (BC) does is essential. A BC is the device divers wear to adjust buoyancy during a dive, and the three common configurations you’ll encounter are jacket-style, back-inflation (often called wings or back-inflate systems), and vest/hybrid designs. The question is looking for the term that identifies the equipment category being discussed, so the best choice is the term that names that category itself. The other items listed aren’t buoyancy compensators: a personal flotation device is a surface flotation device used to stay afloat at the water’s surface, not to fine‑tune buoyancy underwater; a regulator controls air delivery from the tank; a wetsuit provides insulation and some passive buoyancy but isn’t a BC and doesn’t let you adjust buoyancy during a dive.