Pete, when I sail uni i have a small anchor that I tie a line to with a milk jug as a buoy. After launhing the boat, I drop the anchor and tie off my wheels to it right out in the water. When I finish sailing I come in and sail right to my wheels.

BTW, sometimes you need to raise your sails on the water, if so, then you can tie off to the makeshift mooring buoy to do that.