I've been to a well-known ski school with a driver AND an instructor in the boat. I've also been to a respected school where the instructor is also the driver, i.e., the only person in the boat when I'm skiing. He seemed to know what I was doing back there and gave me some good pointers to improve, but I wonder how much he could really see. Anybody have any opinions/experiences with regards to how well a driver/instructor can teach you?