Despite the class being built with operations against the Japanese in mind not a single T class (or any operational British submarine) was left in the theater at the time of the Japanese attack. "Truant" and "Trusty" were ordered to the area with haste but arrived just in time for Singapore to fall. Following the allied retreat they were based out of Ceylon with the surviving Dutch submarines. They were sortied to intercept the expected Japanese route for the Indian Ocean Raid, and "Truant" did sink two IJA transports, but the Kido Butai did not pass that way.