SM U-24 was one of 329 submarines serving in the Imperial German Navy in World War I.

The victim was HMS Formidable, torpedoed 30 nautical miles (56 km; 35 mi) south of Lyme Regis, at 50°13′N 03°04′W / 50.217°N 3.067°W / 50.217; -3.067.

She was hit in the number one boiler room on the port side.

[5] In 1915, U-24 claimed another noted victim, the passenger steamer Arabic, causing 44 deaths, including three Americans.

This escalated the U-boat fear in the U.S. and caused a diplomatic incident which resulted in the suspension of torpedoing non-military ships without notice.