A marine mine is a type of explosive device that is designed to be placed beneath the surface of the water in order to damage or sink ships or submarines. There are several different synonyms for this type of device, including underwater mine, naval mine, sea mine, and aquatic mine. These terms all refer to the same basic concept of an explosive that is used to create hazards in the water for ships and other vessels. Other related terms might include torpedo, depth charge, and underwater explosive device, which are all used to describe different types of weapons that are used in maritime warfare.