http://en.wikipedia.org/wiki/British_commando_frogmen#1944
October 27-28: The British submarine Trenchant carried two Mk 2 Chariots (nicknamed "Tiny" and "Slasher") to an attack on Phuket harbor in Thailand. They were released six miles out from the harbor. The targets were two Italian liners, the Sumatra and the Volpi, each approx 5000 tons. Six hours later, for the only time, the British charioteers rode back to their mothership. On the return journey the Trenchant jettisoned the chariots so it could travel faster, after receiving a report of a Japanese MTB in the area. The Trenchant carried the four charioteers back to Trincomalee. No chariot operations in combat in any war are certainly known of after this.