The Action of 4 April 1918 was a naval action fought in the Atlantic Ocean during World War I

World War I

World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...

. An unknown Kaiserliche Marine

Kaiserliche Marine

The Imperial German Navy was the German Navy created at the time of the formation of the German Empire. It existed between 1871 and 1919, growing out of the small Prussian Navy and Norddeutsche Bundesmarine, which primarily had the mission of coastal defense. Kaiser Wilhelm II greatly expanded...

U-boat

U-boat

U-boat is the anglicized version of the German word U-Boot , itself an abbreviation of Unterseeboot , and refers to military submarines operated by Germany, particularly in World War I and World War II...

 attacked three armed transports of the United States Army

United States Army

The United States Army is the main branch of the United States Armed Forces responsible for land-based military operations. It is the largest and oldest established branch of the U.S. military, and is one of seven U.S. uniformed services...

 and Navy

United States Navy

The United States Navy is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. The U.S. Navy is the largest in the world; its battle fleet tonnage is greater than that of the next 13 largest navies combined. The U.S...

, but failed to damage the American ships before she was sunk.

Action

On April 4, 1918, three armed transports, USAT , and were steaming back to the United States in convoy after having completed a troop transportation voyage to France. At 11:45 in the morning, a German U-boat of unknown designation surfaced and fired torpedoes at Mallory. Lookouts aboard the transport spotted the torpedoes, allowing the ship to successfully evade them.

The submarine was sighted by the other American transports; all three ships opened fire with their main guns, and appeared to hit the U-boat as she submerged. The vessels then maneuvered in close and depth charge

Depth charge

A depth charge is an anti-submarine warfare weapon intended to destroy or cripple a target submarine by the shock of exploding near it. Most use explosives and a fuze set to go off at a preselected depth in the ocean. Depth charges can be dropped by either surface ships, patrol aircraft, or from...

d the last-known location of the Germans. The three American vessels were credited with sinking the attacking submarine. The convoy reached the United States on or about April 13, 1918.

See also

• Action of 8 May 1918
  Action of 8 May 1918
  The Action of 8 May 1918 was a small naval engagement which occurred off Algiers, North Africa during World War I. In the action, an American armed yacht and a British destroyer encountered the German U-boat...
  
  
• Battle of the Atlantic
  U-boat Campaign (World War I)
  The U-boat Campaign from 1914 to 1918 was the World War I naval campaign fought by German U-boats against the trade routes of the Entente Powers...
  
  
• Battle of the Mediterranean
  Mediterranean naval engagements during World War I
  There was sporadic naval warfare in the Mediterranean during World War I between the Central Powers' navies of Austria-Hungary, Germany and the Ottoman Empire and the Allied navies of Italy, France, Greece, Japan, America and the British Empire....