USS Eagle Boat 56 ( PE - 56 ) USS " Eagle 56 " ( PE - 56 ) was a United States Navy World War I - era patrol boat that remained in service through World War II . On 23 April 1945 , while towing targets for US Navy bomber exercises off the coast of Maine , " Eagle 56 " was sunk by the German submarine . Only 13 of the 67 crew survived . The loss was classified as a boiler explosion until 2001 when historical evidence convinced the US Navy to reclassify the sinking as a combat loss due to enemy action . Service history . " Eagle 56 " was one of 60 built by Henry Ford late in World War I as submarine chaser s , none of which saw action . Unpopular due to their poor sea handling , only eight remained in service at the time of World War II . " Eagle 56 " was patrolling off the Delaware Capes in January 1942 . " Eagle 56 " remained almost constantly at sea during the Second Happy Time of the Battle of the Atlantic , during which Axis submarines attacked merchant shipping along the east coast of North America . When her depth charge s were expended , a small ship from Cape May , New Jersey would bring out a new supply . " Eagle 56 " rescued survivors of off Cape May in February . " Eagle 56 " was damaged by collision with the submerged wreck of " Gypsum Prince " while rescuing survivors from the British freighter which had collided with the British tanker Voco on 4 March at the entrance to Delaware Bay . " Eagle 56 " was repaired using parts from another Eagle boat , and then assigned to the Key West SONAR school in May 1942 . Sinking and Investigation . " Eagle 56 " was assigned to Naval Air Station Brunswick from 28 June 1944 . At noon on 23 April 1945 , " Eagle 56 " exploded amidships , and broke into two pieces off Cape Elizabeth , Maine . The destroyer was operating near " Eagle 56 " and arrived 30 minutes after the explosion to rescue 13 survivors from the crew of 62 . " Selfridge " obtained a sharp , well - defined SONAR contact during the rescue and dropped nine Mark IX Mod 2 depth charge s without obvious result . According to a classified Navy report , " U - 853 " had been operating in the waters off Maine . At a Naval Board of Inquiry in Portland the following week , five of the 13 survivors claimed to have seen a submarine . Several spotted a red and yellow emblem on the submarine ' s sail . These insignia match the markings of " U - 853 " : a red horse on a yellow shield . " Eagle 56 " s boiler was overhauled just two weeks before the sinking , and none of the boilers on the other 59 Eagle Boats had failed . Nevertheless , the official Navy inquiry concluded that " Eagle 56 " had suffered a boiler explosion . On 5 May 1945 , " U - 853 " sank the collier " Black Point " off the coast of Point Judith , Rhode Island causing the loss of twelve lives . During the ensuing Battle of Point Judith " U - 853 " was chased and sunk by Navy and Coast Guard ships . On 1 June 1945 , Rear Admiral Felix X . Gygax wrote , " at least equal evidence to support the conclusion that the explosion was that of a device outside the ship , the exact nature of which is undetermined . It might have been an enemy mine or an enemy torpedo . " Ultimately , though , he endorsed the court ' s findings . Because the Allies had cracked Germany ' s codes , United States intelligence knew in 1945 that U - boats had been sent across the North Atlantic to disrupt shipping in hopes of obtaining better surrender terms . However , only general warnings rather than specific information about this plan were passed to commanders . Reclassification . In 2001 , the Naval Historical Center reviewed the case and reclassified the sinking as a combat loss . In June 2001 , Purple Heart medals were awarded to three survivors and the next of kin of those killed . As of 2007 , this is the only time that the US Navy has overruled its own Court of Inquiry .