The world's largest cruise ship Icon of the Seas departs on its maiden voyage from Miami – as nearly 8,000 passengers prepare for a 55-foot waterfall, 40 restaurants and SEVEN pools

The world's largest cruise ship has embarked on its seven-day maiden voyage from Port Miami, with nearly the population of a small town on board.

Royal Caribbean's Icon of the Seas departed today for a seven-day island-hopping voyage in the Caribbean before returning to Miami.

The $2 billion ship measures nearly 1,200 feet (365 meters) from bow to stern and has 20 decks, 2,350 crew members, 2,805 staterooms and space for 7,600 passengers.

In addition, the ship also features an artificial waterfall of 17.5 meters, 40 dining options and bars, seven swimming pools, including a 40,000 liter 'lake', 50 musicians and comedians and a 16-piece orchestra.

The ship is powered by 'environmentally friendly liquefied natural gas'. According to ReutersAccording to Royal Caribbean, the Icon is 24 percent more efficient when it comes to CO2 emissions than required by the International Maritime Organization.

The $2 billion ship measures almost 365 meters from bow to stern and has 20 decks, 2,350 crew, 2,805 cabins and space for 7,600 passengers.

The ship is powered by 'environmentally friendly liquefied natural gas'

The ship also has a structural feature designed as a dynamic art installation on the main access route, called 'The Pearl'.

Royal Caribbean also said that every kilowatt used on the Icon of the Seas is “scrutinized for energy efficiency and emissions reductions.”

But despite claims that the fuel is better than traditional marine fuel, environmentalists believe the ship poses major risks of methane emissions.

According to the International Council of Clean Transportation, methane emissions from LNG-powered ships contribute to climate change in the form of 'methane slip'.

Methane slippage occurs when ships like the Icon use low-pressure dual-fuel engines that tend to leak methane into the atmosphere during the combustion process.

Bryan Comer, director of the Marine Program at ICCT explained: 'It's a step in the wrong direction.

'We estimate that using LNG as a marine fuel emits more than 120% more greenhouse gas emissions during its life cycle than marine gas oil.'

Cruise ship engines have an estimated methane slip of 6.4 percent on average by 2024 research funded by the ICCT, which is 3.5 percent higher than the IMO assumption.

Passengers lounge in the Aquadome area of ​​Icon of the Seas, a diving and performance venue under a glass dome on the top of the ship

An employee walks through the Central Park part of the ship, because it also has its own 'family neighborhood' called 'Surfside'

Despite claims that the fuel is better than traditional marine fuel, environmentalists believe the ship poses major risks of methane emissions

According to the International Council of Clean Transportation, methane emissions from LNG-powered ships contribute to climate change in the form of 'methane slip'.

Lionel Messi will take part in the naming ceremony of the 'Icon of the Seas' in Miami on Tuesday

Michael Bayley, president and CEO of Royal Caribbean International, said: “We built the biggest and baddest ship in the world. It's really exciting when you introduce a new class of ships, but it's even more exciting when it really seems to be perfect.”

Methane is a powerful greenhouse gas and the second largest contributor to climate warming after carbon dioxide, according to NASA Global Climate Change website.

An estimated 60% of current methane emissions are the result of human activities.

But these concerns don't seem to bother owners as the Icon will make year-round Caribbean voyages from Miami, with the itineraries featuring 'idyllic destinations' and stops at 'award-winning private island' Perfect Day at CocoCay in the Bahamas.

The ship was officially 'baptized' by the World Cup winner on Tuesday Lionel Messi and his Inter Miami teammates.

Messi headlined the event, placing a football on top of a stand to 'start' the traditional smashing of a champagne bottle against the ship's bow – something that is supposed to bring good luck to the ship and its passengers.

The 36-year-old Argentinian later called it a 'privilege'.

“It is a great honor for me and I know what it means for the city of Miami and the whole world,” Messi said in Spanish. 'So I call this ship Icon of the Seas. God bless you and all those who sail with her.'

Michael Bayley, president and CEO of Royal Caribbean International, added: “We built the biggest and baddest ship in the world. It's very exciting when you introduce a new class of ship, but it's even more exciting when it really seems perfect.”