'Cook' was a British naval undertaking in which Lieutenant E. Honer’s MGB-318 landed a party to bury half a ton of stores on the Ile Guénioc off the north coast of Brittany in the north-western part of German-occupied France (3 April 1943).

Intended to provide weapons, ammunition and other supplies for the use of the French resistance forces, the undertaking’s first attempt on 25 March had failed as the motor gun boat ran into thick fog after departing Falmouth, but this second effort succeeded.