Inside the world's largest cruise ship: our image tells you everything you need to know about the incredible 300-metre Icon Of The Seas as it undergoes final testing ahead of its maiden voyage

The world's largest cruise ship is en route to Puerto Rico as it prepares to accept its first paying passengers.

Locals and tourists in Ponce, Puerto Rico, got a sneak peek of the 1,200-foot, 250,800-ton pleasure cruiser, dubbed the Icon Of The Seas, as it took a break in port as part of its sea trials necessary to complete its certification to acquire.

The 20-deck ship, five times larger than the ill-fated Titanic, towered over the city on the southern coast of the Caribbean island.

The enormous ship, which cost cruise line Royal Caribbean $2 billion, features a dining room, six swimming pools and the largest water park at sea of ​​any cruise ship in the world.

The inaugural sailing for paying customers will depart from Miami, Florida, on January 27 for a seven-day cruise through the Caribbean, including a stop at 'Perfect Day at CocoCay', Royal Caribbean's private island in the Bahamas.

Our image tells you everything you need to know about the Icon Of The Seas as it undergoes its final testing ahead of its maiden voyage.

Princes' schedule for a seven-day Caribbean cruise starts at around £1,200 this year, but so far almost all 'staterooms' have been booked and paid for, with costs still up for grabs between £4,000 and £6,000 lie.

Some rooms are even more expensive. The Ultimate Family Townhouse suite spans three decks. While customers can choose to take the stairs to walk through the enormous suite, they can also opt for a slide when descending, which opens onto the living room floor.

The Ultimate Family Townhouse accommodates eight people and has its own sun deck and several balconies. Seven nights will set families back a staggering $85,000 (£70,000).

Putting the cruise together took years, with prototypes of 'quarters' – as the eight main parts of the ship are known – being built to scale in Miami before being installed on the actual ship at the Meyer Turku shipyard on the Finnish Baltic coast.

Most of the 'huts' are modular, built elsewhere in Finland and then lifted into place.

The most daring lift came when the Aquadome – the largest free-standing dome at sea, with almost 700 glass panels and a weight of 365 tons – was lifted from the dock and deposited on the ship like a flying saucer, with the weight evenly distributed using number of computers connected to each cable.

This particular maneuver lasted 24 hours and the dome now features a 55-foot waterfall and can accommodate 1,300 people.

Jay Schneider, Royal Caribbean's chief product innovation officer, previously told the Mail: “We didn't set out to create the largest ship in the world.”