A sub sinker is a type of weapon used by submarines to attack other vessels. The term can refer to four different weapons: a MINE (4 letters), an ASHCAN (6 letters), a TORPEDO (7 letters), and a depth charge (11 letters). Mines are explosive devices placed in the water, while ashcans are containers filled with explosives that are dropped into the water. Torpedoes are self-propelled missiles that are fired from a submarine, and depth charges are explosives that are dropped into the water and detonated at a certain depth.