I put on an air dried polyurethane on the clear wood area's you see on my sail boat and after 10 year of use I sold it and the poly coated wood was still in good shape. So it is still hard for me to understand why it isn't used inplace of varnish. This was in the mid 60's when I used this. On the other hand, I used a marine varnish on a racing boat that looked terrible after 5 years. I know there is a lot of experience here using varnish, but what I used was cheap and really held up. Also, the mast was made of several pieces of 2x4's glued together with contact cement and held up perfectly.

John