Powerhead
（重定向自Bang stick）
A powerhead, bang stick, smokie or shark stick is a specialized firearm used underwater that is fired when in direct contact with the target, not to be confused with other types of underwater firearms which fire specially designed projectiles and do not require direct contact with the target. Powerheads are often used for spear fishing and against sharks or alligators for sport, defense, or to kill nuisance animals. The term powerhead refers to the firearm-like part of the device; when attached to a shaft to form a spear, it may be referred to as a bang stick or shark stick. The spear in question may be handheld or launchable from a spear gun.