A man who has lived on cruise ships for more than 20 years can no longer walk in a straight line on land.

Mario Salcedo – known in the cruise community as Super Mario – has been moving between Royal Caribbean ships for more than two decades, claiming he is the ‘happiest guy in the world’.

He used to work in finance for a multi-national corporation, but he sacked it in age 47 and began a new life at sea.

He’s now spent more than 9,000 nights on cruise ships and he said the lifestyle ‘never gets old’ – it’s just his rare returns to land which can be tricky.

He says he’s lost his land legs. Credit: The New York Times/YouTube

“I’ve lost my land legs, so when I’m swaying so much I can’t walk in a straight line,” he told Condé Nast Traveller in 2016.

To live this lifestyle, he budgets around $60-70,000 per year, booking his cruises two years in advance and opting for basic cabins, while also bringing in funds by managing investment portfolios for private clients from on board the ships.

Meanwhile, on port days – when most passengers get off for excursions – he usually stays put on the ship, only stepping foot on land for around 15 days a year.