Also known as a "Hedgehog", these mortars were used as forward firing weapons to attack submarines and some were also used to fire onto a beach in an effort to clear landmines prior to sending troops ashore. This is one of many UXO's (unexploded ordinance) in the lagoon here. Seven inches in diameter, four feet in length, weight 65 pounds ...of which 31 is the explosive. We look but do not touch when we find UXO's.