The Underwater Demolition Assault U

The Underwater Demolition Assault Unit (UDAU)[1] of the Royal Thai Navy (Thai: หน่วยทำลายใต้น้ำจู่โจม) is a 144-man special operations force within the Military of Thailand. The unit is colloquially also known as the Royal Thai Navy SEALs (Thai: หน่วยซีล), the Thai language word for Seals[2] as in the pinniped animals. Although this title was influenced by the US unit, it is not an acronym like the American unit's.
The unit was set up in 1956 with the assistance of the U.S. Government and has trained with United States Navy SEALs it predates. A small element within the Royal Thai Navy's "seal" unit has been trained to conduct Maritime Counter-Terrorism missions. This unit has close ties with the U.S. Navy's own SEAL teams.