To make an 8 inch block, make a 6.5 unfinished HST for the main sail. For the small sail, make a partial flying geese block. Use a rectangle that is cut 2.5 x 6.5. Sew a 2.5 inch square on the diagonal and trim to make a half flying geese for the small sail. sew it to the right of your 6.5 HST.
Make your boat with a 8.5 x2.5 rectangle. sew a 2.5 square of your background fabric to each end on the diagonal and trim. Sew this to the bottom of the sail units and voila! a sailboat block.