noun
buoyancy compensator; BC; BCD
Diving equipment that allows a diver to adjust buoyancy underwater. Often abbreviated as BC or BCD in English.
ダイビングの前に浮力調整装置の点検を忘れずに。
Don't forget to check your buoyancy compensator before diving.
Compound of 浮力 (buoyancy) + 調整 (adjustment) + 装置 (device). A straightforward technical term.