Operation FD (i)

This was a British major naval programme of minelaying using submarines (1940/44).

The first of the sequence was FD.1 of 4 April 1940 when Narwhal laid 50 Mk XVI mines in the Heligoland Bight, and the last was FD.52 of 4/19 December 1944 when the French Rubis laid 30 Vickers TIII mines off Jśrens Rev in German-occupied Norway.