Stalwart-class ocean surveillance ship

The Stalwart-class auxiliary general ocean surveillance ships are a class of United States Naval Ship auxiliary support ocean [surveillance ship]s commissioned between April 1984 and October 2000. Their original purpose was to collect underwater acoustical information using the Surveillance Towed Array Sensor System, a towed array passive sonar.
Stalwart, Indomitable, and Capable were modified to support narcotics interdiction by removing SURTASS equipment and adding an air-search radar and tactical data link equipment.