"Whitesand Bay" proceeded to Sasebo, Japan, to join the British U.N. Task Group. As part of elaborate deception operations intended to make the enemy believe that a major U.N. amphibious invasion actually planned for Incheon on 15 September 1950 would take place at Kunsan, she landed Royal Marine Commandos and United States Army special forces troops on the docks at Kunsan, with those forces making sure that the enemy noticed their visit. She then deployed with Task Group 90.7 for blockade duty under the command of Commander A. N. Rowell. She returned to Hong Kong in December 1950.