Exactly. If they'd wanted to, they could have proposed that boats stop using red, that everyone would have to have new tanks and systems to get rid of the dye, and retailers would have had to sell red and white. But they haven't. They've proposed a system that, as you say, is incredibly difficult to police. But don't forget that the government never wanted to impose this tax in the first place, and it will raise peanuts in government terms. As such, they're not going to put a great deal of effort into trying to enforce it, as the consultation document itself implies. It'll be pointless dipping the tank, because they'll know you'll have red in there.And just look at the figures from the consultation document. The potential revenue from this will be 0.06 per cent of the total revenue from fuel taxes. They say the effort to enforce it will be proportional, which to me suggests that they'll be putting in very little effort. It's not worth spending the time and money for such little return, and on a tax they never wanted in the first place.