The DUKW was designed by Rod Stephens Jr. of Sparkman & Stephens Inc. yacht designers, Dennis Puleston, a British deep water sailor, and Frank W. Speir, an ROTC Lieutenant out of MIT. Developed by the National Defense Research Committee and the Office of Scientific Research and Development, it was initially rejected by the armed services. When a United States Coast Guard patrol craft ran aground on a sandbar near Provincetown, Massachusetts, an experimental DUKW happened to be in the area for a demonstration. Winds up to 60 knots (110 km/h), rain, and heavy surf prevented conventional craft from rescuing the seven stranded Coast Guardsmen, but the DUKW had no trouble, and the military opposition melted. The DUKW would later prove its seaworthiness by crossing the English Channel.
The DUKW prototype was built around the cab over engine (COE) six-wheel-drive military truck GMC ACKWX (a COE version of the GMC CCKW), with the addition of a watertight hull and a propeller. The final production design was based on the CCKW. The vehicle was built by the GMC division of General Motors (called Yellow Truck and Coach at the beginning of the war). It was powered by a GMC Straight-6 engine of 270 in³ (4.416 L). The DUKW weighed 7.5 tons and operated at 6.4 mph (10 km/h) on water and 50-55 mph (80 km/h) on land. It was 31 feet (9.3 m) long, 8.25 feet (2.4 m) wide, and 8.8 feet (2.6 m) high with the folding-canvas top up. 21,137 were manufactured. It was not an armored vehicle, being plated with sheet steel between 1/16" and 1/8" thick to minimize weight. A high capacity bilge pump system kept the DUKW afloat if the thin hull was breached by holes up to 2" in diameter.
The DUKW was the first vehicle to allow the driver to vary the tire pressure from inside the cab, an accomplishment of Speir's device. The tires could be fully inflated for hard surfaces such as roads and less inflated for softer surfaces—especially beach sand. This added to the DUKW's great versatility as an amphibious vehicle. This feature is now standard on many military vehicles.
The DUKW was supplied to the US Army, US Marine Corps and Allied forces. 2,000 were supplied to Britain under the Lend-Lease program and 535 were acquired by Australian forces. 586 were supplied to the Soviet Union, becoming the basis for the BAV 485 (see Developments).
The DUKW was used in landings in the Mediterranean, Pacific, on the D-Day beaches of Normandy, Operation Husky, and during Operation Plunder.
After World War II, reduced numbers of DUKWs were kept in service by the United States, Britain, France and Australia with many more stored pending disposal. Australia transferred many to Citizens Military Force units.
The US Army reactivated and deployed several hundred DUKWs at the outbreak of the Korean War with the 1st Transportation Replacement Training Group providing crew training. DUKWs were used extensively to bring supplies ashore during the Battle of Pusan Perimeter and in the amphibious landings at Inchon.
Ex-US Army DUKWs were transferred to the French military after World War II and were used by the Troupes de marine and naval commandos. Many were used for general utility duties in overseas territories. France deployed DUKWs to French Indochina during the First Indochina War. Some French DUKWs were given new hulls in the 1970s with the last being retired in 1982.
Britain deployed DUKWs to Malaya during the Malayan Emergency of 1948-60. Many were redeployed to Borneo during the Indonesia–Malaysia confrontation of 1962-66. The Royal Marines still use a small number of these vehicles for training purposes in Scotland.