The Ocean Survey Vessel (OSV) Bold was operated by the United States Environmental Protection Agency (EPA). Originally commissioned as the USNS Vigorous, it was renamed USNS Bold (T-AGOS-12) and was a Stalwart-class Auxiliary General Ocean Surveillance ship of the Military Sealift Command of the United States Navy, as designated by the "T" preface to her AGOS classification. Stalwart-class ships were originally designed to collect underwater acoustical data in support of Cold war anti-submarine warfare operations in the 1980s.

Stalwart-class auxiliary general ocean surveillance ships (T-AGOS) are a class of United States Naval Ship (USNS) auxiliary support Ocean Surveillance Ships commissioned between April 1984 and October 2000. Their original purpose was to collect underwater acoustical information using the Surveillance Towed Array Sensor System (SURTASS), a towed array passive sonar.