USCGC Mackinac ( WAVP - 371 ) USCGC " Mackinac " ( WAVP - 371 ) , later WHEC - 371 , was a " Casco " - class United States Coast Guard Cutter in service from 1949 to 1967 . She was the second ship of the United States Revenue Cutter Service or United States Coast Guard to bear the name . Construction and U . S . Navy service . " Mackinac " began life as the United States Navy " Barnegat " - class seaplane tender USS " Mackinac " ( AVP - 13 ) . She was laid down on 29 May 1940 at the Puget Sound Navy Yard at Bremerton , Washington , launched on 15 November 1941 , and commissioned into the U . S . Navy on 24 January 1942 . She operated in the Pacific during World War II , seeing action in the Solomon Islands , in the Marshall Islands , in the Palau Islands , and at Okinawa . She was decommissioned in January 1947 and placed in the Atlantic Reserve Fleet at Orange , Texas . Transferred to the United States Coast Guard . " 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 . The Navy loaned " Mackinac " to the Coast Guard on 19 April 1949 , and the Coast Guard official accepted her at Orange on 21 April 1949 . Coast Guard Cutter USCGC " Tampa " ( WPG - 164 ) then towed her from Orange to the Coast Guard Yard at Curtis Bay at Baltimore , Maryland , where she underwent conversion for use as a weather - reporting ship . While this was in progress , the Coast Guard commissioned her as USCGC " Mackinac " ( WAVP - 371 ) on 11 May 1949 with Commander William L . Maloney , USCG , in command . Her conversion was completed on 18 July 1949 . U . S . Coast Guard service . " Mackinac " was stationed at New York , New York , throughout her Coast Guard career . Her primary duty was to serve on ocean stations in the Atlantic Ocean to gather meteorological data . In addition , she conducted search - and - rescue and law enforcement operations and provided navigational and communication assistance to aircraft . She was among a number of cutters based on the United States East Coast that rotated among four ocean stations in the Atlantic Ocean . While on duty in one of these stations , she was required to patrol a 210 - square - statute - mile ( 544 km² ; 159 nmi² ) area for three weeks at a time , leaving the area only when physically relieved by another Coast Guard cutter or in the case of a dire emergency . While on station , she acted as an aircraft check point at the point of no return , a relay point for messages from ships and aircraft , as a source of the latest weather information for passing aircraft , as a floating oceanographic laboratory , and as a search - and - rescue ship for downed aircraft and vessels in distress . " Mackinac " ' s first base at New York City was at Brooklyn , New York . She shifted her base to St . George , Staten Island , New York , on 17 September 1953 . On 13 November 1953 , she came to the assistance of the merchant ship " Empire Nene " at latitude 41°53 ’ North , longitude 43°47 ’ West . On 1 May 1966 , " Mackinac " was reclassified as a high endurance cutter and redesignated WHEC - 371 . She won the Eastern Area Vessel Performance Award for Fiscal Year 1967 . Decommissioning and disposal . " Mackinac " was decommissioned on 28 December 1967 and placed in storage at the Coast Guard Yard at Curtis Bay . On 21 July 1968 the Coast Guard returned her to the Navy , and she was stricken from the Naval Vessel Register that day . The Navy sank " Mackinac " as a target off the coast of Virginia on 23 July 1968 , using her for target practice by United States Naval Academy midshipmen . " Mackinac " sank in 1 , 800 fathoms ( 10 , 800 feet or 3 , 300 meters of water ) at position 36°22 ’ North , 73°09 ’ West . Although under fire from four ships — heavy cruiser USS " Newport News " ( CA - 148 ) , guided missile light cruiser USS " Springfield " ( CLG - 7 ) , guided missile frigate USS " King " ( DLG - 10 ) , and destroyer USS " New " ( DD - 818 ) — and despite " King " s first Terrier missile scoring a direct hit , " Mackinac " proved hard to sink , and her hull remained largely intact as she slipped beneath the waves .