I finally got my 15 out for it's first sail since I got it in December. Sunday and Monday were absolutely gorgeous on Lake Michigan with 10-knot winds from the Southwest. Waves only about 1 foot. (very calm water) Yesterday, my second day out, I sailed from Evanston down to Chicago's Wilson Ave. water intake crib and back -- my GPS registered 15 miles round trip, with a maximum speed of (I'm not joking) 7.0 mph! This was my first time rigging the M15 and I have a question I hope somebody will be able to answer: From the top of my mast, back side, I have a wire that comes down to a few feet above the deck, on the end of which is a small block (pulley). What is this for? Is it supposed to be part of an adjustable backstay? Or is it part of a topping lift arrangement? Any ideas? (please forgive my inexperience)