I use low-pile industrial carpet on the N20 and the F18. So far it has held up better than the nacra tape and done less damage to the boards (my F18 tape had a seam in the middle of the board well that wore a groove in both my daggerboards from going up and down). Home Depot now carries this low pile (cheap stuff) without the rubber backing; this is important. Glue it in place with contact cement - though I used windshear on the last ones and they're doing just fine. If you use contact cement, keep in mind that you will need to slide the carpet in while it's all wet, then carefully slide a board in place (you'll really have to work a little to keep it from pushing the carpet out of the well) and let it setup.