that I forgot to mention. At the ends of the boat, where the sides are more flat than round, the straps don't work so hot. The engineers lurking around could explain the vector forces involved, but you wind up squeezing the keel against the sheer rather than the sides against the forms. These are also the areas where the strips are most likely to misbehave, too. The link below shows several ways of dealing with this problem. The external form was made by adding 1/4" to the inner form to define the inner shape, rounding out the outer shape and cutting it out of scrap. With this in place, the errant strips snugged right up. The wood dries out with surprising speed, so you can go back to work the next day.

Before you take off the straps though, if you run a fillet of hot glue on each side of the edge of the inner form, the strips will be less inclined to wander off the reservation again. If you do this, take Rob Macks' advice when stripping the deck, and leave a 1/8" gap between the sheer strips. This will allow tool access to bang the forms loose later.