The United States Coast Guard assigned new hull numbers to all lightships still in service in April 1950.

In January 1965 the Coast Guard further modified all lightship hull designations from WAL to WLV, so Chesapeake became WLV-538.

The 30,000 candela main light was also backed up with a secondary lamp and the Radio Locator Beacon also had a backup system.

Coast Guard officers, usually a Warrant Bos'n,[clarification needed] were also placed in command of the lightships, which meant a more efficient, orderly and strict operation.

During World War II, Chesapeake was based out of Sandwich, Massachusetts, where she served as an examination and guard vessel at the north entrance of the Cape Cod Canal and helped protect the important port of Boston.

In the 1960s with the introduction of automated buoys as well as permanent light stations, the lightship fleet was slowly mothballed.

She was then transferred to the National Park Service and used as a seagoing environmental education classroom until she was handed over to the city of Baltimore in 1982.