Hello, I have spent the last few years browsing the internet looking for boat & kayak plans.  Here are a few sites i have run across which have free boat plans.

Free Hereshoff canoe plans

http://www.classicwoodenboatplans.com/canoe_hereschoff.htm

Nick Shade Stitch & Glue Guillemont Kayak

http://www.guillemot-kayaks.com/guillemot/information/kayak_building/stitch_and_glue_construction/free_stitch_and_glue_kayak_plans

Almost 200 Free boat plans

http://www.svensons.com/boat/