GMC amphibious truck (DUKW) being checked for leaks at General Motors Truck and Coach factory

View of workers checking a GMC amphibious truck (DUKW) for leaks at General Motors Truck and Coach factory. Label on back: "By means of a power driven winch the amphibian truck can pull itself out of mud or quicksand with astonishing ease. The winch cable is simply attached to a post, tree or any solid object on shore and the engine-driven winch does the rest. Unbelievable is the term used by engineers in describing the many accomplishments of this unique sea-going truck now being built by General Motors Truck and Coach. Here, it is shown being subjected to the 'bathtub test' for water leaks at the factories of General Motors Truck and Coach before the 20-mile test run which is given every 'duck' before delivery to the Army. (Approved by the War Department, Bureau of Public Relations.)" Handwritten on back: "Amphibious vehicles."