Mast Step lower base

Two Doug Fir wedges were bonded down first, to make a level surface. Then a layer of 1/4 inch ply. Then glassed... why? So if the whole thing needs replacement down the road, I just grind down to the glass and bond in a new mast step. Then, a 5/16 inch ply with these grooves cut to allow water drainage with the bolt holes shown in other detail photos. More details available if asked.