Based on the Coast Guard Historian’s timeline, https://www.history.uscg.mil/research/chronology/
With inspiration from Mike Kelso

USRC Seminole, Amerioca’s Cup Races 1901, Library of Congress

1907  The Commandant, Captain Worth G. Ross, USRCS, by letter, advised the Chamber of Commerce of Baltimore, Boston and Philadelphia, the New York Maritime Exchange and the Navy’s Chief Bureau of Equipment that wireless telegraph sets had been installed on the following Revenue cutters operating on the Atlantic coast and would use the following call letters: USRC Algonquin: RCA; USRC Gresham: RCG; USRC Mohawk: RCM; USRC Onondaga: RCO; & USRC Seminole: RCS.

1936  Executive Order No. 7521 authorized ice breaking operations by the Coast Guard.

1960  The tanker Pine Ridge, with 37 crewmen on board, reported it was breaking in two about 120 miles off Cape Hatteras, North Carolina.  Immediately, the Coast Guard dispatched aircraft and vessels to the scene and alerted nearby US Navy and merchant vessels.  After the arrival of a Coast Guard UF-2G amphibian aircraft, the bow section of the Pine Ridge capsized, throwing some members of the crew overboard; the stern section, however, remained afloat and upright.  Mountainous seas rebuffed every attempt of the tanker Artemis to rescue the seamen in the water.  Life rafts and emergency equipment, meanwhile, were airdropped, and the helicopters from the aircraft carrier Valley Forge successfully removed the 28 survivors from the still floating stern section.  Of the bow section and the 9 missing crewmen, only debris and lifejackets were found, despite a widespread air and surface search.

RVNS Tran Binh Trong (HQ-5) es-USCGC Castle Rock moored outboard of ex-USCGC Cook Inlet (WHEC-384) in South Vietnamese naval service as RVNS Tran Quoc Toan (HQ-6) and ex-USCGC Bearing Strait (WHEC-383) in South Vietnamese naval service as RVNS Tran Quang Khia (HQ-2) at Saigon in May 1972.

1971  The last two cutters of Coast Guard Squadron Three (RONTHREE) in service in Vietnamese waters during the war, CGC Cook Inlet (WHEC 384) and CGC Castle Rock (WHEC 383) were decommissioned and transferred to the South Vietnamese Navy.