as mentionned before, glass in between is no good ! strenght wise !
make the board, easy : to give it rocker and concave i screwed the outside of the board to a very quick made rocker table, basicaly, you just draw the shape of the board on the little to big square pieces of ply ( i used 3 times 5 mm, center one verry holowed to save wheight ) and glued them together, then screwed them on the table, shape holds VERRY well, then, sanded a LOT of material down with power belt sander and finishing with disc sander ( both cheapest tools, work fine ) to thinner board on the edges. sanding is easy as you have the plys from the wood to guide you into how mutch sand where to make it even. made holes on top, put inserts inside, epoxy to fill, sand down, glass botom ( one layer ) wraping a bit on the sides.
i'm there now, have to sand edges, glass top, sand everything and maybe a finishing coat, maybé not on the botom and a finishing coat on the top to make a skateboard like finish to ride it strapless.
still, TO heavy, and, cant find thinner then 1/4 here !! is going to be more off a light wind kiteskate !!
next time, project it to hollow 2 sheets, mirror like, and glue them on the table hollowed face inside, so, i'm going have a 10mm board, but with hollows from 4 to 6 mm on the inside, like the hull of a hollow surf ..... glass, ahd, should be stiff and light.