Expert explains how world's largest cruise ship is able to float after it left people baffled

An engineering expert has explained exactly how cruise ships such as Icon of the Seas are able to stay afloat.

Ever since Royal Caribbean International's megaship came into service earlier this year, people have been left baffled by the sheer size and height of the boat.

Measuring 364m (1,196 ft) by 48m (159 feet), the Icon is the world's biggest cruise ship and boasts of seven (yes, seven) swimming pools as well as an ice skating rink, wave simulator and over 40 restaurants, bars, and lounges.

Now of course, the first thing you or I would think when seeing a photo of the Icon sailing the seven seas is less likely to be awe and more likely 'how the f**k does that thing stay afloat'.

While I'm sure the ship's quite frankly bizarre appearance is easily forgettable once you're onboard and spending your time at the waterpark or playing mini-golf, anyone on land will almost certainly be left shocked by its size.

So, how does the Icon of the Sea stay afloat?

In past couple of weeks, a video of the ship arriving in all its ginormous splendour at the Port of Miami began to do the rounds on social media - which of course had viewers asking the same question.

"Somebody tell me how does this thing manage to float," one person wrote, while another added: "How the s**t does this thing float?"

Curious as to how Icon of the Seas doesn't sink or tip over in the face of choppy waves or strong winds? Don't worry, we have the answer.

Responding to everyone's confusion over the subject, an engineering student realised it was their time to shine and shared a relatively straightforward explanation of Archimedes' law of buoyancy.

"The water is pushing up on the ship with a force equal to the weight of water it pushes aside. Because the ship is so big, it pushes aside a lot of water, creating a strong upward force," they wrote.

Icon of the Seas, aka the floating city, leaving the Port of Miami. (n to build, has 20 decks, and can hold a maximum of 7,600 people. (Joe Raedle/Getty Images))

They continued: "The ship only needs to sink a little bit into the water to float. You can see the waterline - everything below that is pushing water out of the way, creating the upward force that keeps it afloat.

"While parts of the ship (like the hull) are very dense, the overall density of the entire vessel is less than water due to its largely hollow design. This lower average density is what allows such a giant structure to float effortlessly on water."

Still confused? An explainer article from Cruise Nation says a large ship is able to stay afloat 'as long as they can displace an equal amount of water to their mass'.