'CK' (ii) was the designation of Allied convoys (together with a numerical suffix) plying the route from Havana, Cuba, to Key West, Florida (October 1942/August 1943).

The first of this 'Cuba to Key West' series was CK.302 of 16/17 October 1942 with the 7,176-ton US Arthur Middleton, 8,881-ton British Athelregent, 1,109-ton Nicaraguan Corinto, US Hercules, 5,441-ton Cuban Libertad, 990-ton Norwegian Moysalen, 570-ton Cuban Oriente, 5,266-ton US Plymouth, 1,695-ton US Steelmotor, 388-ton Cuban Tropical and 2,450-ton US William C. Atwater. The last was CK.326 of 31 August 1943 with the 1,027-ton Cuban Julian Alonso escorted by the submarine chasers SC-1468 and SC-1472,