There was a newsletter article about the dangers of hanging an ob on the transom of an Ariel or Commander. One of our West Coast members almost went overboard in some choppy conditions trying to reach the engine. In addition, the prop of the transom mounted engine kept coming out of the water in even less rough conditions. After that experience, they put the engine back in the well. Transom mounting is ok if conditions are "normal," but things can get dangerous if conditions turn ugly.