'Chacewater' was a British operation by the Special Operations Executive to organise the protection of 'Foscott' high-priority targets in the Milorg military resistance organisation’s D.16 district of Telemark and Buskerud in German-occupied Norway (21 February/May 1945).

The three-man party, comprising S. Armtsen, A. Larsen and K. Stordalen, was parachuted into its area on 21 February and made contact with the Milorg district leader. Targets for protection in the Kongsberg area were agreed and the training of local groups began. German raids soon followed, however, and in clashes a number of German troops were killed, which led to further raids and the loss of equipment. Nevertheless, by the time of the liberation of Norway in May 1945 'Chacewater' had 300 men under command, and secured the safety of its targets.