Duplex Drive or DD tanks (nicknamed "Donald Duck tanks") were a type of amphibious swimming tank developed by the British during the Second World War.
DD tanks worked by erecting a 'floatation screen' around the tank, which enabled it to float, and had a propeller powered by the tank's engine to drive it in the water.
The DD tanks were one of the many specialized assault vehicles, collectively known as Hobart's Funnies after their commander, Major General Percy Hobart, devised to support the planned invasion of Europe.
Sherman V Duplex Drive (Lowered Screens)
Sherman V Duplex Drive (No Screens)
You can find rules for using DD tanks in the excellent Battleground Europe Theatre Book…