Hi Paul,
just to muddy your thoughts, we've had a "diving duck", a submarine, and a fully rigged with sails thames barge all win on a steering course competition. A lot depends on the course layout and weather too, wind can be a great asset, or a total equaliser on a course. Also knowing your boat, and what happens to the stern as soon as power is applied, and most important of all, you need very good eyesight as on board cameras are not permitted – yet.
As Colin quite rightly points out, it is the skill of the skipper that really counts, you can have all the power and manoeuvrability but one rash control movement, or the tug in the wrong position and everything goes t*%@ up!
Nice to see some rules though, and as Dave W says, you have to watch the experts to appreciate the skills.
Kimmo