Sophie Heawood: If you want to get ahead, get afloat

Summer is here! I know this, not because the sun has reached its highest altitude in the north and entered the tropic of Cancer (that was, like, months ago), not because a family from Hertfordshire have grown a sunflower so large it's about to enter the record books, and not because it's raining.

I know it's summer because the first sightings are in of a famously humdrum Brit doing something frolicsome on a yacht. Prince Andrew, in fact, making merry with a mystery brunette, off the coast of Sardinia. On a big luxurious yacht. Doing crazily raunchy stuff things like putting his arms on his chest, raising his arms into the air, momentarily touching her arms with his arms, and then taking his arms back from her arms to raise his T-shirt and do a funny with it stuck over his head. Arms! T-shirts! Heads! You go, girl!

Apparently she was the wife of another guest on board. And not his new girlfriend. But whatever – this is the thing about yachts – anything you are caught doing on one is instantly amplified in its excitingness, simply because of the location. That sleek white boat is a multiplying integer. Its shiny lounging decks function as raising agents. Its huge engine is the loudhailer of the celebrity soul. A yacht gives any celebrity encounter the kind of instant frisson that dry land could only achieve courtesy of pornographic material, the transfer of bodily fluids, and possibly a car park in Stevenage.

I mean, we all knew that Philip Green had got matey with Kate Moss, but it wasn't until they were photographed together on a yacht that greater interest in their friendship was shown. Sting, some years after his tantric sex claims, showed he still had it going on when he sucked his wife Trudie's toes while afloat. We only really knew for sure that Diana and Dodi were an item when they advertised it so flagrantly on his father's yacht. And it was the final proof that Jude and Sienna were back together when we saw pictures of them kissing at sea.

This law can also work against you – if you're a British politician who's taken to palling around with Russian billionaires, later to find yourself embroiled in an investigation conflicts of interest, it may be better that this hobnobbery didn't take place on a yacht, as Peter Mandelson and George Osborne found out. However dodgy the affair might seem, it will seem 10 times dodgier if it took place on a deck. But as the motor launch is the great PR tool of the age, you can imagine Prince Andrew's publicists being quite keen to get him on one.

Imagine the scene: his people take him to one side and say your ex-wife's been trying to flog your services to the philanthropic advancement of dubious overseas businessmen, and you've not been pictured with an attractive woman since 1993. Tell you what, it's time to get thee to a yacht. Yachts are the new San Lorenzo restaurant.

When Tom Stoppard took two lesser characters from Hamlet and gave them their own play, Rosencrantz and Guildenstern Are Dead, he uncovered a profound truth about the omnipotence of sailing. These two were no strangers to image-conscious princes themselves, and Guildenstern said philosophically to his companion, "You can't not be on a boat." Rosencrantz was confused, protesting that "I've frequently not been on boats!" "No no," explained Guildenstern, "what you've been is not on boats."

So, for all you big shots out there who are wondering about this summer's place to be, wonder no more. Mere mortals can't not be on a boat. Celebrities can't not be on a yacht.