High Quality Content by WIKIPEDIA articles! USNS Effective (T-AGOS-21) is a Victorious-class ocean surveillance ship acquired by the U.S. Navy in 1993 and assigned to the Navy's Special Mission Program. Effective was built by Mc Dermott Shipyards, Morgan City, Louisiana. She was laid down on 15 February 1991 and launched 26 September 1991 and was delivered to the Navy on 27 January 1993 which assigned her to the Military Sealift Command (MSC) Special Missions Program. The mission of Effective is to directly support the Navy by using both passive and active low frequency sonar arrays to detect and track undersea threats.