USNS Impeccable (T-AGOS-23) is an Impeccable-class ocean surveillance ship acquired by the U.S. Navy in 2001 and assigned to Military Sealift Command's Special Missions Program.
Impeccable was built by American Shipbuilding, Tampa, Florida. The contract was awarded on 28 March 1991. The ship's keel was laid down on 15 March 1992, but the Tampa shipyards went bankrupt by November 1993.
The ship is a designated T-AGOS vessel built to tow a Surveillance Towed Array Sensor System. The ship's catamaran-type small waterplane area twin hull (SWATH) design prevents the vessel from rolling in heavy seas and gives additional deck space for storing the acoustic equipment.
The mission of Impeccable is to directly support the Navy by using SURTASS passive and active low frequency sonar arrays to detect and track undersea threats.
On 5 March 2009, the Impeccable was in the South China Sea monitoring submarine activity
On 7 March, a Chinese intelligence ship contacted the Impeccable over bridge-to-bridge radio, calling her operations illegal and directing Impeccable to leave the area or "suffer the consequences."