DUKW, amphibious truck 
National Archives, Washington, D.C.

a 2.5-ton, six-wheel amphibious truck used during amphibious operations in World War II by the U.S. Army and Marine Corps. Its primary use was to ferry ammunition, supplies, and equipment from supply ships in transport areas offshore to supply dumps and fighting units at the beach. The DUKW (an acronym based on D-model year 1942, U-amphibian, K-all wheel drive, W-dual rear axles), called "duck," was shaped like a boat. It had a hollow airtight body for buoyancy and used a single propeller for forward momentum. It was designed according to Army criteria and was based on the Army's 2.5-ton truck. The vehicle was capable of carrying 25 soldiers and their equipment, an artillery piece, or 5,000 pounds of general cargo. At sea the vehicle could maintain a speed of 5 knots, and on land it could go 50 miles (80 kilometres) per hour. The United States produced 20,000 DUKWs during World War II. Through lend-lease the British were provided 2,000 of the trucks. The vehicle was first used in "Operation Husky," the invasion of Sicily in 1943.

In the Normandy Invasion of 1944, DUKWs were used by the infantry, engineers, rangers, artillery, and service support units. By ferrying weapons, troops, ammunition, and supplies to the beaches, they played a vital role in the overall success of the landing. Due to the high seas and to the overloading of vehicles, a number of accidents occurred. At Omaha Beach, for instance, the 1st Infantry Division attempted to deploy its 105-millimetre howitzers, gun crews, ammunition, and sand bags in DUKWs; 12 of the 13 DUKWs of the 111th Field Artillery Battalion sank. Six howitzers from the 7th Field Artillery and five howitzers belonging to the 16th Infantry Cannon Company also went to the bottom of the English Channel. These accidents caused a considerable loss of life. Still, the DUKW was a successful amphibious vehicle. The Engineer Special Brigades at Normandy used the DUKWs to great effect in the race to build-up forces and material. In the Pacific, both the Marine Corps and the Army also successfully employed the DUKW.
Below picture from National Archives

Photo below was submited by Fielding Tyler,

458th Vehicles Ft Story, VA 1946