The Sherman DD (Duplex Drive) tank was designed by the Allies specifically for the D-Day landings; enveloped in a waterproofed canvas screen, the tank was launched at sea from landing craft and then 'swam' slowly to shore, where the screens were deflated, allowing the tanks to operate as fighting vehicles. Exploring the development and modifications of the Sherman DD, this book discusses its many variants, including the prototype Valentine DD tank and its role as a training tank in Britain and limited operational use in Italy, and examines the successes and tragic failures on the beaches of Normandy and further into North-West Europe, including the challenge of crossing the River Rhine.