German submarine U-154 was a Type IXC U-boat of Nazi Germany's Kriegsmarine built for service during World War II.

Although it was believed to be sunk by the Colombian Destroyer ARC Caldas during a short encounter near San Andrés Island in 1944,[2] the U-154 escaped without damage.

The submarine was powered by two MAN M 9 V 40/46 supercharged four-stroke, nine-cylinder diesel engines producing a total of 4,400 metric horsepower (3,240 kW; 4,340 shp) for use while surfaced, two Siemens-Schuckert 2 GU 345/34 double-acting electric motors producing a total of 1,000 metric horsepower (740 kW; 990 shp) for use while submerged.

Her success continued with the sinking of Catahoula, Delvalle, Empire Amethyst and Vineland, all near Haiti and the Dominican Republic.

She sank Tillie Lykes on 28 June 1942, about 100 nmi (190 km; 120 mi) south of Santo Domingo in the Dominican Republic and Lalita, using the deck gun, in the Yucatán Channel on 6 July.

Having made the short trip from Lorient to Brest, the submarine's fifth foray was her longest (109 days) and second most successful.

She was then attacked on 13 March 1944, possibly by the US Navy patrol boat USS PC-469 north of the Panama Canal; only minor damage was sustained.

Oskar Kusch, who had commanded the boat in 1943 and the first month of 1944 and successfully attacked three ships, was court-martialled and shot in May 1944, having been reported by his first officer, Ulrich Abel and his chief engineer, Kurt Druschel for Wehrkraftzersetzung (sedition and defeatism).

[5] Kusch had removed Hitlers portrait from the boat and had repeatedly called him an idiot and described the Nazis as tapeworms.