I'm a former M-15 owner (too many years ago, when I had the perfect boat but not the sense to realize it or the time to enjoy it) who is thinking seriously about returning to the fold. In the past I have owned a J-22, and I'm not sure this will work with a M-15, but you can very effectively scull a J-boat just by rocking it from side to side. Easiest way is for one person to stand athwartships, feet on the cockpit coaming or the settees, facing forward, and start her rolling from side to side, steering with the tiller. Good for getting around a marina and into a slip. No reverse, however. As I say, I don't know if this will work with a M-15, but someone might want to try it. Wouldn't want to do it over any great distance, though.