Inside Carnival's new $1.2 billion cruise ship

The new AIDAnova cruise ship. Photo / Supplied

A gigantic new cruise ship that cost a staggering $1.2 billion to build has taken to the high seas for the first time, and it's definitely turning heads.

The latest Carnival vessel is decked out in a rather interesting design — a huge smiling face with bold red lips is painted on the front. It also has a bizarre name — AIDAnova — which is a far cry from the company's typical monikers such as Legend, Triumph, Spirit and Magic.

At 337m long, it's the fifth-biggest ship in the world. Royal Caribbean's Symphony of the Seas is currently the largest on the planet, at 362m and it can squeeze on a handful more passengers (80, to be precise).

It definitely has the wow factor. Photo / AIDA Cruises

The ship weighs a whopping 184,000 tonnes and features 23 bars, 17 restaurants, a beach club, floating TV studio, theatre, water slides, a rock climbing wall and an outdoor gym.

And for the wealthy, there's a massive surprise in the Penthouse Suite which extends over two decks and has robotic staff.

But perhaps the coolest thing about this vessel is something passengers can't really see, and it comes as the biggest surprise. It's designed to be kinder to the environment, and instead of running on diesel it is powered by liquefied natural gas, which is a world-first.

Its launch attracted quite the crowd. Photo / Getty Images

More than 25,000 people flocked to the Meyer Werft shipyard in Papenburg, Germany on Friday for the vessel's christening ceremony, which featured DJ David Guetta.

In mid-September the ship will head to Eemshaven in the Netherlands to undergo sea trials and a final outfitting, before being delivered to the cruise line on November 15 in Germany.

Inside the ship. Photo / AIDA Cruises

The colourful interior is eye-catching. Photo / AIDA Cruises

It's scheduled to make its inaugural voyage on December 2, from Germany to the Canary Islands.

The 337m-long ship can accommodate 6600 passengers, cast and crew. Photo / AIDA Cruises

Here, she will remain for the rest of the season.