'GAT' was the designation of Allied convoys (together with a numerical suffix) plying between Guantánamo, Cuba, via Aruba, Netherlands West Indies, to Trinidad, and as such reciprocals of the 'TAG' series (August 1942/May 1945).

The route was inaugurated in July 1942 as the 'WAT' series, and the first of the 209 GAT convoys was GAT.1 of 31 August/7 September 1942 with 36 merchant vessels. The last of the convoys was GAT.208 of 13/18 May 1945 with 10 merchant vessels.