Abstract: An underwater spear gun of the rubber-band powered type, in which a spear is provided having a plurality of upwardly-projecting tail fins. The spear-shaft is positioned within a bore of a barrel, which barrel has longitudinal channel formed in an outer peripheral surface extending the entire length of the barrel through which project the tail fins. Each rubber band used for powering is stretched about one tail fin. The spear gun also has a unique triggering mechanism directly connected to the line-release lever for a safer and more easily handled gun.