Meanwhile, the shape of the board comes from these ribs, cut from a template downloaded off the Internet, printed to paper and glued to a board. It's not easy to find free, effective templates. Your best bet is to buy one, from about $100, from pros such as www.grainsurfboards.com . I had to modify and tweak the downloaded design here, aiming for a 6'2'' single-fin that's very wide at 22'' for easy paddling and stability.  Photo 7 of 26 in Crafting a Hollow Wood Surfboard from Old-Growth Redwood