Fighting the U-boats

Weapons and Technologies

Detection and Tactics

Code breaking

Probably the biggest and most deadly secret of the allies was the incredibly successful code-breaking at Bletchley Park, England.

British radars

One of the biggest threats to the U-boat force was the allied radar. Here you can find a good overview on those.


The High Frequency Direction Finder ("Huff Duff") was without doubt one of the most dangerous aces the allies had up their sleeve.

ASDIC / Sonar

This was the main detection device used on a submerged U-boat in World War Two and has been dramatized in numerous movies through its distintive "ping" sound.

The Leigh Light

Huge search lights that were fitted to medium and large bombers on U-boat patrols in the Atlantic.


Device to detect submarines underwater, alternative to hydrophones.

Magnetic Anomaly Detection

Another clever device to detect submerged U-boats - heavily used by allied aircraft later in the war.


Depth Charges

The most common anti-submarine weapon of World War Two.


These was a forward-throwing device which cast 24 projectiles into the water ahead of the ship. These only exploded on contact.


Small rockets that were fitted to aircraft and used by fighters and bombers to attack U-boats.

Mk. 24 Fido torpedo

Air launched acoustic-searching torpedo that was very successful in hunting U-boats.

Read about the American torpedo problems early in the war