I'm a novice sailor. In the latest sail magazine, thier is an article on main sail trim. I'm a little confused on some of the tactics they use. Twisting a main sail. 1. Opening a batton 2. opening and closing leech and clew. i know leech and clew by name only. I was out on the weekend. Had fun using a mainsheet traveler i rigged up. played with the main sheet tension to see the affects. how and when to use boom vang tension? should knowing this be beneficial to a slow cruiser? bryan