Abstract: A spear gun assembly for propelling a sharpened spear in an underwater hunting environment. The assembly includes a holding bar rigidly attached to the gun which engages a hole in the spear. A trigger assembly is actuatable to pivot a lifter for lifting the spear from the holding bar, thereby releasing the spear from the gun. The trigger assembly is provided with a safety mechanism for preventing the lifter from pivoting and a lanyard which is disengaged as the trigger is actuated.