I meant to just add 1/8th of an inch all round, along the full length of both sides of the plank and at the ends.
If you really want to save wood and the time to trim it, can I suggest that you get some tracing paper and trace each plank/board onto some stiff card and try each piece onto the hull formers in card before you transfer the shape to wood. Card cuts easier than wood with a pair of scissors!!!!
I have done that with other clinker models and found it to be easier and much less wasteful of timber.
A good art shop will have stiff tracing paper (try and get it on a roll rather than folded sheets - no creases) and card up to A2 size. If you want it bigger try a printers.
I moved in the opposite direction to you. I lived in Ripon - 60 miles from the sea - until I went to sea in 1959, then when I was 34 I met a Shields Lass and I am still here 35 years later.
If you need any help or support with your model, send me a PM and I will let you have my phone number.