Wiki: "Many sources incorrectly report that U-120 sank due to a malfunctioning toilet. This submarine was actually the much larger U-1206." "U-1206 was one of the late war boats fitted with new deepwater high-pressure heads which allowed them to be used while running at depth. Flushing these facilities was extremely complicated and special technicians were trained to operate them. On April 14, 1945, 8 miles (13 km) off Peterhead, Scotland, while cruising at a depth of 200 feet (61 m), misuse of the new head caused large amounts of water to flood the boat. According to the Commander's official report, while in the engine room helping to repair one of the diesel engines, he was informed that a malfunction involving the head caused a leak in the forward section. The leak flooded the submarine's batteries (located beneath the toilet) causing them to release chlorine gas, leaving him with no alternative than to surface. Once surfaced, U-1206 was discovered and bombed by British patrols, forcing Schlitt to scuttle the submarine. One man died in the attack, three men drowned in the heavy seas after abandoning the vessel and 46 were captured. Schlitt recorded the location as 57°24′N 01°37′W but the wreck could not be relocated. During survey work for the BP Forties Field oil pipeline to Cruden Bay in the mid 1970s, the remains of U-1206 were found at 57°21′N 01°39′W in approximately 70 m (230 ft) of water. The site survey performed by RCAHMS suggests that the leak that forced U-1206 to surface may have occurred after running into a wreck located at the same site. A large number of sources attribute this incident to U-120." "Submarine heads face the problem that at greater depths higher water pressure makes it harder to pump the waste out through the hull. As a result early systems could be complicated with the head fitted to the US S class being described as almost taking an engineer to operate. Making a mistake resulted in the waste being expelled back into the body of the submarine. The toilet on the World War 1 British E class was considered so poor by the captain of HMS E35 that he preferred the crew to wait to relieve themselves until the submarine surfaced at night. As a result many submarines used the heads as an extra storage space for provisions."