the one off approach i'd recommend is just building a foam armature (yakshape) and glassing that. this procedure is really nicely outlined for a squirtboat in last summers Rapid magazine from canada.

(making a mould is really necessary only for multiple yaks. and is a time consuming expensive step. involving lots of glass and major finishing.i suggest you dont have the time or money)

i'd personally cut the layup on the sheer, popit off, and seam it together afterwords in a light layup. then add/glue on foam etc to the armature where screwed up or too tight,fill in the sawlines and do a good layup then.

sand and finish off just like all of us do here for our wood yaks.

forget the wood, its just for us idiots here who have time to waste. you need results.

even after reading the books, take the dimensions off a yak you like(or even better one you don't like), and then make a whole bunch of modifications to your PRIOR (so the design becomes YOURS) requirements. the dimension takeoff is for guideline ONLY - so you don't get too far out of whack to what you need. do not take the actual lines off the yak(just the dimensions) as they'll likely will become to set in your thinking and predetermine YOUR approach.

-mick