The DUKW (GMC type nomenclature, colloquially known as Duck) is a six-wheel-drive amphibious modification of the 2+1⁄2-ton CCKW trucks used by the U.S. military during World War II and the Korean War. Designed by a partnership under military auspices of Sparkman & Stephens and General Motors Corporation (GMC), the DUKW was used for the transportation of ...