What we did, which works exceptionally well, was to purchase one of those convertible moving carts that work either as two or four wheels after moving the handles, at Home Depot. Then, we had a large piece of plywood cut to fit onto it as a base when it is in four-wheel mode. The weight of your stuff holds the board in place so you don't even need to bracket it down. Works great even when we haul a big load of stuff out a mile onto the Choptank pier.