If red diesel is cheaper in some places than niormal diesel then I find it nuts that paying for fuel for a leisure activity is cheaper than paying for it to fill the car to go to work.
http://www.ybw.com/forums/showthread.php?t=305495 indicates precisely the opposite with only ~30% indicating that they aren't going abroad in 2012 or hardly ever go abroad at all. That leaves 70% that plan to go abroad in 2012... Now that's only a sample of 161 boats (as I write) so statistically poor but it doesn't lend itself to your assertion either...
Save someone's life ... http://https://www.mind.org.uk/donate
Sailing boats motor to a varying degree. Motorboats motor 100% of the time, and they support the economy of the leisure marine industry in general terms.
Smoking and drinking are hardly sport or past times, like darts and snooker are.
You pay VAT on all your climbing gear, but nothing more towards the cost of the NHS to patch you up when you fall off the cliff !
So why not just supply normal diesel and dump the fiction that most is being used for heating?