Take a10mm plywoood , shape the outline and the rails and then put one layer of fibergalss on bottom without rocker table ,cover it with nylon that doesnt stick to the resin remove all the airbubbles with a squigee(I dont know how to spell it). When it drys, put two layers on top, do the same like bottom, then put it on rocker table and put some weights on it. Sand in the end not too much, if there are too many pinholes put a car filler or another layer fo resin.
This is the easiest way I think, u can also do it without a rocker table, just with wedges on each side but I dont reccomend.
If u have questions ask, and post the photos when finished.