You might also consider actually shaping the foam extention so that it is closer to a wave piercing design than the current shape of the bow. As to how to approach the project, you might try contacting Ben Hall at Hall spars and have him send you the information of his renovation of a Waterat A-Class cat. The project was dubbed the Flyingrat. You should be able to attempt this extention by roughing up the gelcoat/paint in the area that you are attaching the foam to, getting the shape of the foam so that it fits over the end of the existing hulls. Epoxy glass to the inside to stiffen and strengthen the foam. Use a structural filler (West System has a few good fillers for this) and then fit it on. Glass the outside of the foam, use carbon fiber toe at the connection point if you feel that the hinge point needs greater stiffening than glass will give you. I would look at approaching the actual connecting joint as a scarf joint. This would allow you to increase the surface area of the epoxy joint. Anyway, good luck with the project. You can find Ben Hall's email address on the usaca web site. I will try to attach the Flyingrat file to another posting.