Wreck of Canadian Ship Sunk by Nazi Spy Submarine Found Off Maine

The wreck of the SS Cornwallis, a Canadian merchant ship torpedoed off Maine during World War II, has been discovered nearly 400 feet beneath the ocean surface. The German submarine responsible for the sinking had secretly brought two Nazi agents ashore in Maine just four days earlier.

The New Hampshire-based Nomad Exploration Team announced this week that it located the vessel in July after years of expeditions. Searchers faced cold water, powerful currents and remote search locations before identifying the wreck with side scan sonar. Subsequent dives confirmed that it was the Cornwallis. Dive team member Danny Allan said the discovery brought renewed attention to a tragedy largely forgotten outside the families and communities connected to the ship.

Built in Vancouver, British Columbia, the 5,458-ton steamship was launched in 1921 under the name Canadian Transporter. It became the Cornwallis after its transfer to Canadian National Steamships. The 400-foot vessel survived an earlier German submarine attack while anchored in Barbados on Sept. 11, 1942. Torpedoes inflicted severe damage, but the ship sank only partially in shallow water and returned to service after repairs.

Its final journey began in Barbados in November 1944, carrying sugar and molasses toward St. John, New Brunswick. Nautical historian Eric Wiberg said the ship carried a 4-inch gun, a 12-pound gun and machine guns mounted on the bridge. None of those weapons were fired.

On Dec. 3, 1944, the German submarine U-1230, commanded by Hans Hilbig, spotted the Cornwallis along the Maine coast. A torpedo hit near its bow, and the merchant vessel disappeared beneath the water in less than 10 minutes. Six of the 48 people aboard reached life rafts, but one died from hypothermia. Fishing boats rescued the remaining five, who were transferred to a U.S. Navy vessel and taken to Rockland, Maine.

The submarine had landed agents Erich Gimpel and William Colepaugh near Hancock, Maine, on Nov. 29. Their assignment was to collect intelligence in the United States. According to a 2018 Main Line Today article, Colepaugh was an American who had traveled to Germany that year for espionage training. Both agents reached New York City without detection.

After the sinking, American authorities investigated whether the attacking submarine had also delivered enemy agents. The FBI subsequently learned that Hancock residents had noticed strangers in the area around the time of the attack. The espionage mission unraveled when Colepaugh confessed to a friend, who alerted the FBI. Gimpel was arrested days later. A military court sentenced both men to death, but those sentences were later reduced to life imprisonment.

U-1230 survived the war before being scuttled in 1945. The Cornwallis remained missing for decades. Following its discovery, the Nomad Exploration Team described the wreck as an “underwater time capsule” connected to an unusual wartime episode along Maine's coast.