German submarine U - 853 German submarine " U - 853 " was a German Type IXC / 40 U - boat of the " Kriegsmarine " during World War II . Her keel was laid down on 21 August 1942 by AG Weser of Bremen . She was commissioned on 25 June 1943 with " Kapitänleutnant " Helmut Sommer in command . " U - 853 " saw action during the Battle of the Atlantic in World War II . She conducted three patrols , sinking two ships totalling 5 , 783 tons . On her final patrol , " U - 853 " was sent to harass United States coastal shipping . She destroyed USS " Eagle 56 " ( PE - 56 ) near Portland , Maine . Just days before Germany ' s surrender , " U - 853 " torpedoed and sank the collier " Black Point " during the Battle of Point Judith . American warships quickly found " U - 853 " and sank her east of Block Island , Rhode Island , resulting in the loss of her entire crew . " U - 853 " is a popular deep sea diving site . She rests in of water . Holes in the hull permit access to the interior of the submarine , though it is a war grave with most of the 55 crew bodies remaining inside . Construction and crew . " U - 853 " was a German Type IXC / 40 submarine built by AG Weser of Bremen . Ordered on 5 June 1941 , her keel was laid on 21 August 1942 and she was commissioned on 25 June 1943 . She was one of 87 submarines of her type . The Type IXC / 40 was a large ocean - going submarine designed for sustained operations far from the home support facilities . " U - 853 " carried a crew of 55 . The Germans nicknamed the U - boat " der Seiltänzer " ( " the Tightrope Walker " ) , and her crew painted an emblem of a yellow shield with a red horse on her sail . First patrol . On her first patrol from May to June 1944 , " U - 853 " was assigned to weather - watching duty under the command of " Kapitänleutnant " Helmut Sommer . This was his first war patrol . German intelligence believed that weather conditions in the Atlantic could be used to help predict the timing of an Allied invasion of Europe . On 25 May 1944 " U - 853 " spotted the " Queen Mary " , loaded with American troops and supplies . The U - boat submerged to attack , but was outrun by the much larger and faster ship . As she surfaced in the " Queen Mary ' s " wake " U - 853 " was attacked by Fairey Swordfish aircraft from British merchant aircraft carrier s and . The U - boat took no significant damage and returned fire , hitting all three aircraft . The planes were able to return to their carrier , but after recovery one was deemed a total loss and jettisoned . The escort carrier had been hunting weather boats for nearly a month and had already sunk and . Intercepted radio transmissions led " Croatan " and six destroyers to search for " U - 853 " . The " U - 853 " proved so elusive that " Croatan " < nowiki > ' < / nowiki > s crew nicknamed their prey " Moby Dick . " After ten days of hunting , on 17 June Huff - Duff ( HF / DF , high frequency direction finding ) picked up a weather report from the " U - 853 " only away . Within minutes two FM - 1 Wildcat fighters strafe d the submarine , killing 2 men and wounding 12 others . Sommer suffered 28 shrapnel and bullet wounds yet still managed to give the order to submerge . In all likelihood Sommer saved his submarine from being destroyed by allied bombers . Three weeks of pursuit from 25 May until 17 June placed an enormous strain on " U - 853 " s crew . Twenty - three - year - old " Oberleutnant zur See " Helmut Frömsdorf took command of the boat on 18 June ( his first command ) and returned to Lorient . Sommer and a large number of the crew was declared unfit for duty . On 10 July Sommer was formally relieved by " Oberlutenant " Otto Wermuth . Second patrol . The boat remained in port until 27 August . Decorated veteran " Korvettenkapitän " Günter Kuhnke , Commander of the 10th U - boat Flotilla , took command for her second patrol . " U - 853 " operated this time in the Western Approaches off the British Isles , but in a period of seven weeks scored no successes . On completion she did not return to Lorient , but continued to Flensburg , arriving 14 October . Kuhnke assumed command of the 33rd U - boat Flotilla upon arriving at Flensburg . He relinquished command of " U - 853 " back to Frömsdorf , who took the U - boat on her third and final patrol . Before departure " U - 853 " was fitted with a " Schnorchel " , a retractable air intake and exhaust that allowed the ship to remain submerged while running her diesel engines . The " Schnorchel " reduced the need to spend dangerous periods on the surface recharging batteries . Last patrol . On 23 February 1945 Germany sent " U - 853 " on her third war patrol to harass US coastal shipping . Under the command of " Oberleutnant zur See " Helmut Frömsdorf , " U - 853 " did not sink any targets during the first weeks of her patrol . Her crossing of the Atlantic was slow because she used her " Schnorchel " to remain submerged to avoid being spotted by Allied aircraft . On 1 April 1945 " U - 853 " was ordered to the Gulf of Maine . On 23 April she fatally torpedoed USS " Eagle Boat 56 " ( PE - 56 ) near Portland , Maine . The next day USS " Muskegon " ( PF - 24 ) made sonar contact and attacked " U - 853 " , but failed to destroy her . " Eagle Boat 56 " , a World War I - era patrol boat , was towing targets for a United States Navy dive - bomber training exercise off Cape Elizabeth when she exploded amidships and sank . Only 13 of the 67 crew survived . Although several survivors claimed to have seen a submarine sail with yellow and red insignia , a Navy inquiry attributed the sinking to a boiler explosion . The Navy reversed its findings in 2001 to acknowledge that the sinking was due to hostile fire and awarded Purple Heart s to the survivors and next - of - kin of the deceased . Battle of Point Judith . On 5 May 1945 , President ( " Reichspräsident " ) of Nazi Germany Karl Dönitz ordered all U - boats to cease offensive operations and return to their bases . " U - 853 " was lying in wait off Point Judith , Rhode Island at the time . According to the US Coast Guard , " U - 853 " did not receive that order , or less likely , ignored it . Soon after , her torpedo blew off the stern of SS " Black Point " , a collier underway from New York to Boston . Within 15 minutes " Black Point " had sunk in of water less than south of Point Judith . She was the last US - flagged merchant ship lost in World War II . Twelve men died , while 34 crew members were rescued . One of the rescuing ships , Yugoslav freighter SS " Kamen " , sent a report of the torpedoing to authorities . The US Navy organized a " hunter - killer " group that included four American warships : , , , and . The group discovered " U - 853 " bottomed in , and dropped depth charge s and hedgehog s during a 16 hour attack . At first the U - boat attempted to flee , and then tried to hide by lying still . Both times it was found by sonar . The morning of 6 May 1945 two K - Class blimp s from Lakehurst , New Jersey , K - 16 and K - 58 , joined the attack , locating oil slicks and marking suspected locations with smoke and dye markers . K - 16 also attacked with 7 . 2 - inch rocket bombs . Numerous depth charge and hedgehog attacks from " Atherton " and " Moberly " resulted in planking , life rafts , a chart tabletop , clothing , and an officer ' s cap floating to the surface . With the loss of all 55 officers and men , " U - 853 " was one of the last U - boats sunk during World War II . and , with " U - 881 " , the last to be sunk in US waters . " Atherton " and " Moberly " received credit for the kill . Wreck . " U - 853 " lies seven miles east of Block Island in of water . The US Coast Guard pinpoints the location of the wreck at 41 . 13 N 71 . 27 W . " U - 853 " sits upright with her periscope rising to a depth of . Most of the 55 crew member bodies remain within the hull , which is a war grave . It is one of the more popular dive sites in Southern New England . The hull has depth charge blast holes : one forward of the conning tower at the radio room and another in the starboard side of the engine room . Entering the wreck is dangerous due to debris , sharp metal edges , and confined spaces . On 6 and 7 May 1945 , Navy divers attempted to enter the wreck to recover the captain ' s safe and the papers within , but failed . Recreational divers first visited the site in 1953 . In 1960 a recreational diver brought up a body from the wreck . This provoked former navy admirals and clergy to petition the US government for restrictions on disturbing the dead . The German crewman was buried with full military honors in Newport , Rhode Island . At least two recreational divers have died from exploring the wreckage . Renowned deep sea diver Stephen Hardick perished in 2005 while filming the U - boat . He surfaced unconscious and could not be revived . Hardick , age 60 , died as the result of saltwater drowning associated with poor health according to the Rhode Island Medical Examiner ' s office .