I think the issue for many boaters will be whether it is just worth the money in the future. My boat easily gets through 80 litres an hour and whilst I probably could afford running costs of £120 per hour I don't think this represents a good use of my cash. When a return trip, Dover- Calais, is going to cost well over £300 in fuel alone I won't be doing many of those in the future!
There comes a point with any activity when the costs outweigh the benefits. I think power boats will have reached that stage by 2009 for many people- unless you are one of the super rich who just don't care