Where I live, I have a hard time finding cedar boards that are relatively free of knots, but knot-free pine boards are much easier to find, and much cheaper. I know that pine is heavier than cedar, but is that small weight difference enough to make a difference after the boat is finished? In other words, how much of the total weight of the boat comes from the wood itself? Also, are there any other significant differences between cedar and pine that I am overlooking? Thanks for your input.