Nearly simultaneously, the four divers rolled off the side of the vessel and plunged into the blue, cool, choppy river. Slowly and carefully, they descended through the murky water with bright lights mounted on their foreheads. As they went deeper, their visual range dropped to about ten feet. Most of their descent was obscure. The location of their target was not known with great precision. The bearing of 38 08’ 10”N and 76 33’ 10”W was only an approximation. At a depth of seventy feet, in near total blackness, two of the divers sensed a large dark shadow in their peripheral vision. They signaled to the others as their powerful legs propelled them toward the mysterious object. They cautiously approached the shadow which measured two-hundred-twenty feet in length.  Their lights eventually clarified that the huge dark shadow was the object they were seeking. It was an enemy submarine; a German submarine, known as an Unterseeboot, or U-boat.

This particular vessel is U-1105. It is a very special U-boat; only ten of this type were manufactured. Launched in June 1944, late in World War II, it was a new breed of U-boat made with the primary objective of avoiding Allied sonar. This objective was achieved by coating the U-boat with a layer of rubber which absorbed sonar signals and made the vessel essentially invisible. In addition, it could remain submerged for sixty days by using a long and wide-bore snorkel which allowed , sufficient fresh air inside to enable breathing for the crew of forty-four and allowed the diesel generators to function under water. U-1105 had a range of eight-thousand, five -hundred miles and carried fourteen torpedoes. Its top speed was 17 knots, which was considerably faster than the Liberty Ships in Allied convoys, which were its primary target. U-1105 earned the name “Black Panther.” It was reported that, in 1944, under attack by the British, U-1105 once sat silently on the bottom for thirty hours and remained undetected. In that era, it was the most advanced and technologically sophisticated submarine in the world.

At the end of the War, in May 1945, the captain of U-1105 surrendered his vessel to the British. They studied it and passed it on to the US Navy. The US Navy studied it at MIT in Boston, Solomons Island in Maryland, and the Naval Gun Factory in Washington, D.C. In August 1948 the Navy decided to scuttle U-1105 in the center of the Potomac River two miles south of Herring Creek in eighty feet of water.
No one paid much attention to U-1105 until 1985 when sport divers discovered it. It is now a diving site maintained by the Maryland Historical Trust as Maryland’s first historic shipwreck preserve. A buoy is placed over the site from April until December each year to mark the site for professional divers. Permission to visit the site is required from the Maryland Historical Trust. The U-boat is now covered with undersea growth and debris.
An interesting video is available on U-Tube if you google:
U-1105 black panther historic shipwreck. The video is courtesy of Southern Maryland Divers.