SAS
Special Air Service
Three squadrons of the Australian SAS Regiment served in Vietnam on a rotating basis between 1966 and 1971. (The New Zealand SAS were also deployed as part of the Aussie squadrons.) Their primary mission was Long Range Reconnaissance, operating from dawn to dusk in complete silence. Losing only two men during the war, the SAS had the highest kill ratio of any unit in Vietnam.
See
AATTV