Between 8 and 9 PM, a low-flying Heinkel He111 is seen dropping magnetic mines by parachute in the Thames Estuary at Shoeburyness. 2 mines land on mud flats that are very shallow and uncovered at low tide. Two officers with the Render Mines Safe group (HMS Vernon), Lieutenant Commanders John Ouvry and Roger Lewis, are summoned to the Admiralty and dispatched by Churchill himself to recover the mines. These mines have caused the loss of 50,000 tons of shipping since October 16 and countermeasures are crucial.
In the Bay of Biscay, U-43 torpedoes French merchant ship SS Arijon, en route from Antwerp for Buenos Aires (cargo of steel bars).