I was blown away by life on board the world's largest cruise ship: you can have everything you want, from a breakfast cocktail in the world's largest suspended infinity pool at sea to a £70,000-a-week three-storey floating mansion

This is it. The lumbering, slobbering, glowing apex predator of the cruise industry, weighing 250,000 tons and measuring 1,150 feet in length – Royal Caribbean's Icon of the Seas, the largest cruise ship in history.

It's been many years in the making – and now it's finally out at sea. And honestly, so am I.

The experience of boarding the inaugural sailing in Miami is overwhelming. In front of me is a work of art that resembles a giant golf ball and a swarm of Royal Caribbean employees, all in orange T-shirts, standing there. Nearby, a man holds a clipboard next to a life-size bronze statue of, for some reason, a dog defecating on a lamppost.

My short trip coincides with the launch of a partnership between Royal Caribbean and the Inter Miami football team, including Lionel Messi. They are an irresistible couple. The greatest footballer of all time, adopted by the greatest cruise ship of all time. Somewhat predictably, Royal Caribbean has called Messi “the icon of the icon.”

With a weight of almost 300,000 tons and a length of 350 meters, Royal Caribbean's Icon of the Seas is the largest cruise ship in history

With the size, the hyperbole, and the sheer strangeness, it takes 24 hours to acclimatize. At first I hardly know which way I'm looking. And even if I am in the know, I don't turn a blind eye when I see a huge plastic flamingo, nor when I am attacked by two exuberant Mexicans with sportswear that resembles a donut and a fried egg.

'How did you sleep?' the Donut asks in a sing-song falsetto. Not bad, I say. 'Don't forget to wash your hands!' chimes in the fried egg.

This colorful madness is a world unto itself. Hardly influenced by the waves, it moves according to its own rhythms and rules.

Rule 1. You can get what you want. A breakfast cocktail? Help yourself. Basketball? No problem. A climbing wall? A shopping mall? We've got you covered, sir.

Rule 2. Participate. There are so many activities available that it would be a crime not to try them out. It's a chance to do things you love, and a few things you've never done before.

I explore the water slides, which stretch across the upper deck like bleeding organs. The pressure drop is not a problem, as it turns out. But the Frightening Bolt is full-on.

One morning I try the fastest growing game in America. Pickleball is played on a small court, with a small plastic bat and a plastic ball. It's easy to pick up and loads of fun.

Thomas practices his short game on a miniature golf course on the sunny deck aboard the enormous ship

The Icon of the Seas features the world's largest floating water park and infinity pool

The Ultimate Family Townhouse is spread over three floors, accommodates eight people, has a musical staircase and a slide. It can be yours for €70,000 per week

That afternoon I take part in a napkin folding course. Because I think: if not now, then when? There is confusion and there is no teacher. Luckily, another gambler – Mike from Dallas – works in the hospitality industry and steps in to take the class. I soon became absurdly proud of my Diamond Fold. Returning to my room, I fold all the linens and towels into diamond shapes.

My 'stateroom' is nice, by the way. Not huge, but cleverly put together, with a balcony and sea views. All that for about €2,600 per week.

For larger expenses there is the Ultimate Family Townhouse. Spread over three floors, with eight sleeping places, a musical staircase and a slide. It can be yours for €70,000 per week.

After building the world's largest passenger ship, with the world's largest suspended infinity pool at sea and the world's largest floating water park (and so on), it's unconvincing for Royal Caribbean to claim it has no obsession with size. “The size issue happened by accident,” emphasizes Jay Schneider, the company's chief product innovation officer. 'It was never our intention to make the largest ship in the world. We just wanted it to be the most iconic.”

You can get what you want. A breakfast cocktail? Help yourself. Basketball? No problem. A climbing wall? A shopping mall? We've got you covered, sir

A bar on board the liner. Royal Caribbean Chief Product Innovation Officer Jay Schneider said: “We never set out to create the largest ship in the world. We just wanted it to be the most iconic.”

A stateroom on the luxury ship, with sea views, costs £2,600 per week

But every few years the company makes a ship that is a meter longer than the previous one. It's oops, we did it again.

More compelling is the company's claim that it has created the world's best vacation for kids. Forget Disneyland Paris. This theme park floats. It will be pure heaven for the little ones.

They might even play pickleball against some of the world's greatest soccer players. At the end of my trip, for the naming ceremony, the entire Inter Miami team – including Luis Suarez and Messi themselves, appear on the ship in their pink strips. As a reward, they receive vouchers that allow them and their family members to take a cruise at any time.

That must be some consolation for Messi – who, according to Forbes, has earned an estimated $1.15 billion (900 million euros) in his career to date.

A suitably crazy spectacle follows in the spectacular Aqua Dome. There's a bagpipe performance by a rock band called the Red Hot Chilli Pipers; blessings from a rabbi and a priest. Then the great Lionel Messi dutifully slams a barrel of Veuve Clicquot against the hull and says: 'I call this ship Icon of the Sea.'

And the job is done – until the next largest cruise ship in the world comes along.