Use ,marine grade carpet like is used in bass boats. Your Lowes should have it. Regular carpet, once rained on, holds water and will add a lot of weight. I once owned an alum. canoe and I purchased the marine carpet and glued it down wth contact cement in the bottom and up the sides. Marine grade carpet is thin and once it is glued down, water will run off it to the back where you can take the drain plug out to drain the boat after fishing. If you take your time and cut the carpet to fit before glueing it down, it will look good plus you will be able to use a water hose to clean it.
Fly fishing and fly tying are two things that I do, and when I am doing them, they are the only 2 things I think about. They clear my mind.