UDT 25

About UDTs Underwater Demolition Teams (UDTs) were a precursor to the current United States Navy SEALs. The UDT’s conducted beach and hydrographic reconnaissance, explosive cable and net cutting, explosive destruction of underwater obstacles to enable major amphibious landings, limpet mine attacks, submarine operations, and the locating and marking of mines for minesweepers. They also conducted river surveys and foreign military training. While doing this, the UDTs pioneered combat swimming, closed-circuit diving, underwater demolitions, and midget submarine (dry and wet submersible) operations. [source: Wikipedia]