Minelaying cruiser HMS Adventure is damaged on a mine for the second time, in Liverpool Bay en route from Milford Haven, Wales. She is towed into Liverpool (under repair until May when she is further damaged in an air raid,finally returning to service on June 27).
350 miles West of Ireland, Italian submarine Luigi Torelli attacks a small convoy of 6-7 merchant ships, sinking Norwegian SS Brask (12 crew killed, 20 rescued) and Greek SS Nemea (17 crew killed, 14 rescued).
Overnight, 76 RAF bombers raid the naval base at Wilhelmshaven, Germany. Wellington bombers of No. 57 Squadron attack Emden, Germany.