The origin of the Navy SEALs can be traced back to the Underwater Demolition Teams (UDTs) of World War II. These units were responsible for clearing obstacles and mines from beaches and harbors in preparation for amphibious landings.
Underwater Demolition Teams (UDT), were amphibious (water bound) units withing the US Navy. These teams of “Frogmen” were created by the United States Navy during World War II with specialized non-tactical missions.