The early phase of the

Battle of the Atlantic The Battle of the Atlantic, the longest continuous military campaign in World War II, ran from 1939 to the defeat of Nazi Germany in 1945, covering a major part of the naval history of World War II. At its core was the Allies of World War II, ...

during which

German Navy The German Navy (, ) is part of the unified (Federal Defense), the German Armed Forces. The German Navy was originally known as the ''Bundesmarine'' (Federal Navy) from 1956 to 1995, when ''Deutsche Marine'' (German Navy) became the official ...

U-boat U-boats are Submarine#Military, naval submarines operated by Germany, including during the World War I, First and Second World Wars. The term is an Anglicization#Loanwords, anglicized form of the German word , a shortening of (), though the G ...

s enjoyed significant success against the British

Royal Navy The Royal Navy (RN) is the naval warfare force of the United Kingdom. It is a component of His Majesty's Naval Service, and its officers hold their commissions from the King of the United Kingdom, King. Although warships were used by Kingdom ...

and its Allies was referred to by U-boat crews as ''the Happy Time'' (), and later the First Happy Time, after a second successful period was encountered. It started in July 1940, almost immediately after the Fall of France, which brought the German U-boat fleet closer to the British shipping lanes in the Atlantic. From July 1940 to the end of October, 282 Allied ships were sunk off the north-west approaches to

Ireland Ireland (, ; ; Ulster Scots dialect, Ulster-Scots: ) is an island in the North Atlantic Ocean, in Northwestern Europe. Geopolitically, the island is divided between the Republic of Ireland (officially Names of the Irish state, named Irelan ...

for a loss of of merchant shipping. The reason for this successful Axis period was the British lack of

radar Radar is a system that uses radio waves to determine the distance ('' ranging''), direction ( azimuth and elevation angles), and radial velocity of objects relative to the site. It is a radiodetermination method used to detect and track ...

and huff-duff-equipped ships which meant that the U-boats were very hard to detect when they made nighttime surface attacks

ASDIC Sonar (sound navigation and ranging or sonic navigation and ranging) is a technique that uses sound propagation (usually underwater, as in submarine navigation) to navigate, measure distances ( ranging), communicate with or detect objects o ...

(

sonar Sonar (sound navigation and ranging or sonic navigation and ranging) is a technique that uses sound propagation (usually underwater, as in submarine navigation) to navigate, measure distances ( ranging), communicate with or detect objects o ...

) could only detect submerged U-boats. When it ended is a matter of interpretation, with some sources claiming October 1940 and others extending it to April 1941, after the Germans lost three prominent U-boat commanders: Günther Prien, Joachim Schepke, and Otto Kretschmer.

References

Battle of the Atlantic {{Germany-WWII-stub

See also

References