Roman Abramovich loses 'world's biggest yacht owner' title to Emirati royals' £390m, 590ft super-yacht New mega-yacht took four years to design and build and is largest in world It is owned by Sheikh Khalifa bin Zayed al-Nayan, president of the UAE Chelsea owner Abramovich's 533ft Eclipse now just second-largest in world The Emirati royal family now rule the waves after it was revealed they own the world's biggest mega-yacht, knocking Russian oligarch Roman Abramovich's off the top spot. The Chelsea owner's vessel Eclipse had been the world's biggest yacht for the past three years, but it has now been usurped by Azzam which is 54ft (16.5m) longer - the length of a football field penalty area. The 590ft (180 metre) super-yacht is set to launch a new round of one-upmanship among the world's super-rich. Battle: The Emirati royal family now rule the waves after it was revealed they own the world's biggest mega-yacht, knocking Russian oligarch Roman Abramovich's off the top spot Ownership of the £390million craft has been shrouded in secrecy, but Yachts France, which creates the annual mega yacht league table, revealed it belongs to Sheikh Khalifa bin Zayed al-Nayan, President of the United Arab Emirates and Emir of Abu Dhabi. Longer than 12 double-decker buses, not only is Azzam the biggest superyacht, it is also expected to be one of the fastest. The 94,000 horsepower vessel could reach speeds of more than 30 knots, or 35mph. Sailing into the record books: The Emirati Royal Family now rule the waves after it was revealed they own the world's biggest mega-yacht, knocking Russian oligarch Roman Abramovich's off the top spot For the playboy who has everything: Azzam the £390m superyacht blows everything else out of the water Longer than some cruise ships: Azzam is described as the 'most complex and challenging yacht' ever built The size of superyachts has grown as billionaires compete to own the largest and its builders boast that Azzam, which means dedication in Arabic, is the 'most complex and challenging yacht that has ever been built'. It was designed by Nauta Yachts and constructed in Bremen by Lurssen - she was floated out in April. The firm's Peter Lurssen said: 'She truly represents another milestone in yachting history.' The yacht requires a staff of 50, and interior features include a 29ft salon and a stunning, open-plan interior. Ownership of the £400million craft which is bigger than Roman Abramovich's superyacht has been shrouded in secrecy, but Yachts France, which creates the annual mega yacht league table, revealed it belongs to Sheikh Khalifa bin Zayed al-Nayan, President of the United Arab Emirates and Emir of Abu Dhabi French interior designer Christophe Leoni was briefed to produce a sophisticated and yet timeless interior with a turn-of-the-century, Empire style. It is likely to match the luxury of Abraovich's Eclipse, which features an armour-plated master suite, two swimming pools, two helipads, a hall, a cinema, a mini-submarine and even its own missile defence system. Abramovich has owned Eclipse, which is valued at £740million, since it was launched in 2010. You wouldn't want to turn around in a hurry: Azzam is 54ft longer than Abramovich's yacht Eclipse Abramovich's yacht Eclipse is smaller but boasts essentials such as two heliports,several jacuzzis and bulletproof glass It took the title of world's biggest private yacht from the 454ft Rising Sun, owned by American businessman Larry Ellison, which in turn took over from the 414ft Octopus, owned by Microsoft co-founder Paul Allen. Azzam's design suggests it has been built for a buyer in the Middle East as it has about 50 suites but no large open spaces on deck, said TheYachtPhoto's Peter Seyfferth. 'I have never seen an Arab-owned yacht with big parties and girls round the pool like the Russians have,' he said. It is unlikely it will leave its dock very often. It is more of a question of prestige, to have the world's largest yacht.' Of the top 100 yachts featured in the list, 31 were owned by people from the Middle East, 19 were Russian owned, and 17 belonged to Americans. Small fish: Giorgio Armani leaves his yacht Mariu measures 50 metres Small change: Tiger Woods' yacht Privacy which measures 47 metres At 590.6ft long, Azzam is longer than 12 double-decker buses parked end-to-end. At her widest point, known as the beam, Azzam measures 68.2ft, while her hull is 15.8ft deep. She's heavier than Eclipse, too, with an estimated gross tonnage of 14,000GT - roughly equivalent to 1,750 adult African elephants. Powered by two gas turbines and two diesel engines, she will boast an impressive 94,000 horsepower and a top speed in excess of 30 knots. The world's largest super-yacht, Azzam, has been commissioned for a mystery owner and launched in Germany today Azzam's fuel tank can hold one million litres and she will have a top speed of in excess of 30 knots. It took the world's top engineers one year to design Azzam and three years to build her - but this is considered super-quick in ship-building terms. Interior features will include a 29ft salon and a stunning, open-plan interior. Roman Abramovich's Eclipse is 533.1ft long and 72.2ft wide, and has an estimated gross tonnage of 13,500GT. Eclipse, owned by Abramovich, has been revered by yachting enthusiasts for years on account of her size She has four diesel engines and a maximum speed of 22 knots, which means Azzam will far outstrip her should the billionaire owners decide to have a race. The yacht can accommodate 36 guests in comfort, and boasts a cinema, conference facilities, children's playroom, beauty salon, dance floor, swimming pool and sauna. Built by Blohm +Voss Shipyards and designed inside and out by Terence Disdale, Eclipse was custom-made for the Chelsea oligarch in 2010. Both ships are so huge, they would have trouble fitting into the majority of the world's marinas. Only a handful, including Monaco and Antibes on the Riviera would be large enough to accommodate them. However, despite Azzam eclipsing Eclipse today, neither of them comes close to the Titanic in terms of scale. Built in 1912, the ill-fated Titanic was 882ft long and 92ft wide.