|Ordered:||18 March 1911|
|Laid down:||5 February 1912|
|Launched:||24 May 1913|
|Commissioned:||6 December 1913|
|General characteristics Ocean-going diesel submarine|
|Class and type:||German Type U 23 submarine|
|Length:||64.70 m (212.3 ft)|
|Beam:||6.32 m (20 ft 9 in)|
|Draught:||3.45 m (11 ft 4 in)|
|Test depth:||about 50 m (160 ft)|
|Boats & landing |
|Complement:||4 officers, 31 men|
Her second kill was the most significant. The victim was HMS Formidable, torpedoed 30 nautical miles (56 km; 35 mi) south of Lyme Regis, at . She was hit in the number one boiler room on the port side. Out of a crew of approximately 711 men, 547 died as a result. This was one of the largest ships sunk by U-boats during the war.
In 1915, U-24 claimed another noted victim, the passenger steamer Arabic, causing 44 deaths, including three Americans. Arabic sank in 10 minutes. 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.
Summary of raiding history
|26 October 1914||Amiral Ganteaume||France||4,590||Damaged|
|1 January 1915||HMS Formidable||Royal Navy||15,000||Sunk|
|2 April 1915||Lochwood||United Kingdom||2,042||Sunk|
|4 April 1915||City Of Bremen||United Kingdom||1,258||Sunk|
|10 April 1915||The President||United Kingdom||647||Sunk|
|11 April 1915||Frederic Franck||France||973||Damaged|
|27 June 1915||Edith||United Kingdom||97||Sunk|
|27 June 1915||Indrani||United Kingdom||3,640||Sunk|
|27 June 1915||Lucena||United Kingdom||243||Sunk|
|28 June 1915||Dumfriesshire||United Kingdom||2,622||Sunk|
|28 June 1915||Armenian||United Kingdom||8,825||Sunk|
|29 June 1915||Scottish Monarch||United Kingdom||5,043||Sunk|
|30 June 1915||Thistlebank||Norway||2,411||Sunk|
|1 July 1915||L. C. Tower||United Kingdom||518||Sunk|
|1 July 1915||Sardomene||Kingdom of Italy||2,000||Sunk|
|1 July 1915||Welbury||United Kingdom||3,591||Sunk|
|6 July 1915||Ellen||Denmark||169||Sunk|
|7 August 1915||Geiranger||Norway||1,081||Sunk|
|12 August 1915||Osprey||United Kingdom||310||Sunk|
|13 August 1915||Cairo||United Kingdom||1,671||Sunk|
|19 August 1915||Arabic||United Kingdom||15,801||Sunk|
|19 August 1915||Dunsley||United Kingdom||4,930||Sunk|
|19 August 1915||New York City||United Kingdom||2,970||Sunk|
|19 August 1915||St. Olaf||United Kingdom||277||Sunk|
|24 August 1915||Sinsen||Norway||1,925||Captured as a prize|
|25 December 1915||Van Stirum||United Kingdom||3,284||Sunk|
|26 December 1915||Cottingham||United Kingdom||513||Sunk|
|26 December 1915||Ministre Bernaert||Belgium||4,215||Sunk|
|28 December 1915||Huronian||United Kingdom||8,755||Damaged|
|28 December 1915||El Zorro||United Kingdom||5,989||Sunk|
|11 July 1916||Nellie Nutten||United Kingdom||174||Sunk|
|30 October 1916||Nellie Bruce||United Kingdom||192||Sunk|
|10 December 1916||Agder||Norway||305||Sunk|
|21 March 1917||Stanley||United Kingdom||3,987||Sunk|
|22 March 1917||Svendsholm||Norway||1,998||Sunk|
|27 March 1917||Glenogle||United Kingdom||7,682||Sunk|
|28 March 1917||Cannizaro||United Kingdom||6,133||Sunk|
|18 June 1917||Elele||United Kingdom||6,557||Sunk|
|18 June 1917||English Monarch||United Kingdom||4,947||Sunk|
- Helgason, Guðmundur. "WWI U-boat commanders: Rudolf Schneider (Royal House Order of Hohenzollern)". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 21 December 2014.
- Helgason, Guðmundur. "WWI U-boat commanders: Walter Remy (Royal House Order of Hohenzollern)". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 21 December 2014.
- Helgason, Guðmundur. "WWI U-boat commanders: Otto von Schubert". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 21 December 2014.
- Helgason, Guðmundur. "WWI U-boats: U 24". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 4 November 2012.
- Rickard, J. (1 November 2007). "HMS Formidable". historyofwar.org. Retrieved 4 November 2012.
- Helgason, Guðmundur. "3. Escalation - The U-boat War in World War One". German and Austrian U-Boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 4 November 2012.
- Helgason, Guðmundur. "Ships hit by U 24". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 21 December 2014.
- Gröner, Erich; Jung, Dieter; Maass, Martin (1991). U-boats and Mine Warfare Vessels. German Warships 1815–1945. 2. Translated by Thomas, Keith; Magowan, Rachel. London: Conway Maritime Press. ISBN 0-85177-593-4.