For a lower cost alternative, you can make a sailbox out of wood for under $100. Now making two, one for trailer, other for storage at Sail Sand Point. Boxes will be 11.5 ft by 2ft, 10in deep. Lid, 3/8in plywood, with 1 by 2 in edge. Sides and bottom 1/2 plywood. 1 by 2in framing with 2 by 4 ends. Paint inside and out with white semigloss exterior paint. Had the last one for over 20years, and sold with H-17 and trailer.
Caleb