How a German WWII Era U-Boat Became a Shipwreck in Maryland’s Potomac River

When you think of shipwrecks, most people think of old sailing ships wrecked off the coast of the Carolinas or Florida. But Maryland has a unique shipwreck in the Potomac River – a World War II era German U-boat. But the U-boat’s tale and how it came to be in the Potomac River is not a tale of just combat, but one of military research and development.

From its launch in Emden to its final resting place off Maryland’s shores, German submarine U-1105—nicknamed the “Black Panther”—embarked on a remarkable journey of innovation, combat, and scientific intrigue. Commissioned on 3 June 1944 under Oberleutnant zur See Hans-Joachim Schwarz, this Type VII-C/41 U-boat blended cutting-edge technology with wartime daring, only to become a Cold War research subject and, decades later, a forgotten wreck waiting to be rediscovered.

U-1105 was born from Germany’s drive to outpace Allied anti-submarine tactics. Built at Nordseewerke Shipyard in Emden, she measured 67.10 m long with a pressure hull spanning 50.50 m, displaced 759 t surfaced (860 t submerged), and could dive to 230 m. Powered by twin Germaniawerft diesel engines and Siemens-Schuckert electric motors, she could sprint at 17.7 knots on the surface or slip beneath the waves at 7.6 knots. Armament included five 53.3 cm torpedo tubes with fourteen torpedoes, an 8.8 cm deck gun, and enhanced anti-aircraft coverage via a 3.7 cm Flakzwilling M43U and twin 2 cm C38 mounts.

Beyond firepower, U-1105 carried two secret weapons. First was “Alberich,” a synthetic rubber skin of anechoic tiles designed to scatter sonar pings—so rare that fewer than ten U-boats wore it, earning this boat her “Black Panther” sobriquet and conning-tower emblem. Second was the Balkongerät, an advanced 48-hydrophone passive sonar array that doubled the detection capability of earlier systems. Together, these innovations made U-1105 among the stealthiest submarines afloat.

In spring 1945, she prowled convoy routes off Blackrock, Ireland. After slipping past an Allied destroyer patrol, she found three British destroyers of the 21st Escort Group. From 2,000 m away the U-boat launched two acoustic torpedoes; fifty seconds later the first struck HMS Redmill, the second cratering her stern. Thirty-two sailors perished. Forced below by depth charges, U-1105 rode out an unrelenting 31-hour hunt at 570 ft, then—undetected—slipped away until Germany’s surrender. On 10 May she surfaced at Loch Eriboll to hand over her flag to the very escorts she had attacked.

Post-war, U-1105 became a research prize. Temporarily redesignated N-16 under Royal Navy care, she transited to Lisahally before transfer to the U.S. Navy. Arriving Portsmouth, New Hampshire, in 1946, her rubber tiles and sonar gear were dissected by the Naval Research Laboratory and MIT’s Acoustic Laboratory. Subsequent salvage and towing trials in Chesapeake Bay preceded her final mission: on 19 September 1949, a 250-lb depth charge shattered her hull, and she settled upright at 91 ft off Piney Point.

Lost to memory until 1985, sport divers led by Uwe Lovas rediscovered the “Black Panther,” remarkably intact and draped in seasonal marine growth. In 1994 Maryland designated the site its first historic shipwreck preserve, safeguarding U-1105’s tale for future generations.

Today, the secrets of U-1105’s design and service remain a testament to naval ingenuity—and a caution for modern explorers. Diving is strongly discouraged; those who wish to view this artifact must first register their intent with the Maryland Historical Trust and adhere to strict preservation guidelines.

Article by multiple contributors

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