In some Renaissance Italian city states, it was the custom of rich families to vie with each other to put up the highest buildings. Something very similar is going on among the plutocrats who dominate the luxury yachts market.

Ships are getting bigger. If your rival has a 160m yacht, make yours 162m. Or 165m. “Bigger is always better,” laughs Jonathan Beckett, chief executive of the yacht broker Nigel Burgess. “It’s a phenomenon — the market has exploded.’’ This scramble is led by a collection of the super-rich drawn from the ranks of Russian oligarchs, Indian billionaires, hedge fund managers, tycoons, Greek shipping owners — anyone who can put down up to €500 million (£340 million) for an ocean-going vessel.

“Fifteen years ago, if you sold a boat of 50m it was a fantastic deal,” Mr Beckett said. But he believes there is a cut-off point, with anything between 30 and 50 people who want and can afford such ships chasing the 12 afloat.

“There aren’t 50 boats. There will be. That’s not an infinite market. I think then you reach saturation point, when prices will settle.”

David Barrie, director of The Art Fund, which buys works for public galleries, sees no such saturation point at the top end of the art market, after recent record auctions.

“People keep comparing the situation to the late 1980s when there was another huge boom in the art market. That was followed by a huge bust. But there’s no sign of prices flagging.”

Surely they must eventually fall? “If you take a historical perspective, the answer has to be no. At the very least the market is going to calm down and prices must level off. I don’t think it’s a bubble that’s going to burst.

“The top end of the art market today is dominated by rich individuals. In the past, it was rich individuals and rich galleries.”

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