From April 1943 until October 1944, Rockaway delivered supplies and personnel to outlying bases in the North Atlantic Ocean.

She transferred a complete seaplane squadron from Newfoundland to England, carried aviation cargo from Norfolk to the aircraft carrier USS Ranger (CV-4) at Scapa Flow in the Orkney Islands, delivered secret radar equipment to England to be used in the invasion of Normandy of 6 June 1944, performed guard ship duty at Casablanca, French Morocco, for two months, and transported aircraft engines to the Azores.

During the invasion of Normandy in June 1944, Rockaway performed sundry duties for 20 days, including patrol and convoy work in the English Channel; flagship duty for Admiral J. Wilkes, USN; transportation of United States Army and U.S. Navy personnel; and protection of Allied beachheads against German air attacks.

After a shipyard period in November 1944, Rockaway was based in the Panama Canal Zone, completing two trips to the Galapagos Islands with aviation supplies and personnel.

In December 1944 she rescued 13 survivors from a PBM Mariner flying boat which had crashed in the Pacific Ocean off Coco Solo, Panama.

Reclassified as a miscellaneous auxiliary and redesignated AG-123 on 30 July 1945, her conversion was designed to allow her to carry 50 correspondents during the invasion of Japan, which was scheduled for 1945–1946.

Barnegat-class ships were very reliable and seaworthy and had good habitability, and the Coast Guard viewed them as ideal for ocean station duty, in which they would perform weather reporting and search and rescue tasks, once they were modified by having a balloon shelter added aft and having oceanographic equipment, an oceanographic winch, and a hydrographic winch installed.

After undergoing conversion for use as a weather-reporting ship, she was commissioned into the Coast Guard service as the cutter USCGC Rockaway (WAVP-377) on 10 January 1949.

Rockaway was stationed at Governors Island in New York City, which remained her home port throughout her Coast Guard career.

Rockaway conducted a fisheries research cruise from Nova Scotia to Cape Hatteras between 2 March 1971 and 3 April 1971.