Hi Nick You have a valid point. However your possible problem could be overcome by carrying a couple of 20 litre cans of the new duty paid diesel for emergency use only. So if you do misjudge the amount you need, there should be enough of the expensive stuff to get you out of trouble. If you had to divert to a French port 'cos of weather or whatever, you are not likely to upset the authorities either. As things stand, they don't mind red diesel in the main fuel tanks but they do apparently object to red in auxilary cans.
-------------------- I'd sooner be out on the water.