The LCVP/ Higgins Boat
The principle amphibious assault craft of D-Day, all of the United States' troops landed on the beach in one of the literally thousands of boats on duty. Dwight D. Eisenhower emphasized its importance stating “If Higgins had not designed and built those LCVPs (Landing Craft, Vehicle and Personnel), we never could have landed over an open beach."
M4 Sherman Tank
The war horse of the United States' armor, the Sherman was the most common tank in production after 1940. During the invasion of D-Day, some tanks were transported by a flotation device under the tank, and were propelled by a boat-style motor; however, an issue with the flotation caused some tanks to sink before reaching shore, thus sometimes drowning its crew. The vast majority of Shermans were transported by larger transport ships after the initial invasion began.