USNS Vanguard (T-AG-194) Navy Patch

The USNS Vanguard (T-AG-194) was a former World War II tanker (SS Mission San Fernando) converted into a vital U.S. Navy special mission ship, serving primarily as a mobile platform for testing submarine navigation systems (TRIDENT I/II) after 1980, replacing the USS Compass Island. Originally a missile tracking ship (T-AGM-19) for NASA (Apollo, Skylab) and the Eastern Range, it was reclassified in 1980, had its large antennas removed, and was later deactivated in 1998 before being sold for scrap in 2013. 

4 3/4 inch diameter Navy Patch