Past poster (many years past) while building a S&G Artic Tern and long time lurker. Most assuredly a beginner but ready to build another kayak after getting back to a settled place with time etc. I'm hooked on trying one of Mr. Yost's designs and have picked the Sea Tour 15 EXP but have a couple of questions...First, I have a piece of FREE mahogany that is almost 17' and 14.5" wide and CLEAR. It is a full one inch thick and since the price is right seems like the right board to use to cut my stringers, gunwales etc. - I know it will be heavy but since the price is right thought it would be worth it -especially for my first one! Thoughts? Also, does anyone have the Sea Tour 15 EXP offsets converted to either millimeters or to fractions? I plan to draw right onto my 1/2" plywood but am sure I can't be anywhere near precise enough in decimal feet or centimeters with my ruler :-). Ohh - i plan to use the kayak for fishing and exploring protected waters - maybe some ocean kayaking too when not too rough. I'm a little over 6' and weigh 215lb. since my board is almost 17' should i maybe go for the 17EXP and could I just build it a little bit shorter? Thanks for any responses and I look forward to being more active in this community.