I use my boat at least four times a week. Sometimes it's a sunset cruise, other times it's an all-day fish-a-thon. Using it so often improves its antifouling performance. How? Water rushing past the hull helps wash away barnacles and weeds. But even a boat that's constantly used can't rid itself of slime. A thick, opaque goo, slime coats hulls and robs performance. Here's one way to keep a boat's bottom slime-free: Apply Interlux Micron Extra bottom paint, which contains Biolux, a chemical that fights slime the way a good topside wax fights fading. I tested the paint, and except for a thin layer on the submerged portion of the transom, my boat's bottom was free of slime. Plus, Micron Extra self-polishes to a smooth finish by wearing away as your boat runs. No craters or rough surfaces translate into a smoother running surface and a more efficient boat. The best benefit of all? It can last several seasons-after applying three coats last year, I could launch this year without painting. Micron Extra covers 440 square feet per gallon and is available in black, red, dark and light blue, green, gray, and brown.