The Pacific Command Water Transport Company, RCASC, was a secret freight-patrol shipping unit of the Canadian Army based at Vancouver, British Columbia, during the Second World War.

The company was tasked with resupplying camps established to build a telephone line from British Columbia to Dutch Harbor, Alaska, after the Aleutian Islands Attu and Kiska were occupied by Japanese Imperial Forces.

Upon completion of the communication link, the Water Transport Company was assigned with resupplying freight and personnel to remote Royal Canadian Air Force radar stations on the west coast of British Columbia, basing ships at Coal Harbour, Port Alberni, and Prince Rupert.

The company also towed targets for Royal Canadian Artillery coastal gunnery practice.

Ships in the Water Transport Company, RCASC, sailed under their own distinctive flag, a maritime blue ensign with crossed swords on the fly.