Many modern yachts have very powerful engines. This one is using hers to travel at hull speed – or flat out. You can tell she can’t go faster by checking out the huge hollow in the wave form along her hull.
It’s tempting to ‘give it heaps’ when you’ve revs to spare, but a boat gulps down massively more fuel at hull speed than she does at three-quarters of this magic figure. That’s also around the best speed a typical yacht can make close-hauled, so there’s a useful guide. She’ll also create dramatically less wash, so the harbourmaster will be pleased as well.