When their £225 million ($410 million) superyacht cruised into London last week, Tower Bridge had to be raised to let it through.
But when it comes to the extraordinarily lavish lifestyle of owners Andrey Melnichenko and his glamorous wife Aleksandra, the floating palace is just the tip of the iceberg.
Boasting an £8.5 billion fortune, the couple are not shy about splashing their cash in the most extravagant ways.
A palace near the Queen's
They love to jet around the globe, but even billionaires need somewhere to call home, and Andrey and Aleksandra have a dazzling property portfolio to choose from.
In London, the tycoon once snapped up a Berkeley Square apartment from property developer Christian Candy for £2.9 million in 2002, although he no longer owns it.
But that's a mere pied-a-terre compared with the couple's 35-acre Ascot estate, a short chauffeur-driven hop from the Queen at Windsor, which has been valued at £24 million. It has formal gardens, parkland and forest, a separate building housing a spa and swimming pool and another for staff accommodation.
The three-storey property was originally home to Middle Eastern royalty and had 20 bedrooms and 20 living rooms. But the Melnichenkos thought everything was a little tired, and quickly renovated it.
Restyled by French interior designer Jacques Garcia, it is decorated with antique black and white marble floors and 18th-century French furnishings.
Aleksandra - who likes to be known as Sandra - supervises the interior design of all her properties.
In Moscow, the couple - who have a four-year-old daughter - are believed to own a home in a settlement just outside the city, where neighbours include several former Russian officials.
Andrey owns a £9 million 2,800 sqft duplex penthouse overlooking Central Park in New York, which he is said to have paid for in cash. Then there is the obligatory villa in the South of France - in their case in the aptly named Billionaire's Bay, Cap d'Antibes, where a property won't leave you much change from £100 million.
Neighbours include fellow Russian Roman Abramovich, as well as the Heineken family.
Priceless art in every room
The £225 million maiden voyage of his superyacht was reportedly to southern Norway to "pick up" three Monets.
Aleksandra is said to sleep next to two enormous works from the artist's Water Lilies series and is a fan of the French impressionists.
All the couple's homes - floating and otherwise - are decorated with artwork worthy of the best galleries. Indeed, they have loaned some of their collection to museums.
When Russian Vogue visited the Ascot estate back in 2011, they found a marble hallway lined with sculptures by 18th-century artist Jean-Baptiste Pigalle, works by contemporary artist Marc Quinn (he is also responsible for a giant orchid sculpture in the garden) along with two canvases from 20th-century Italian Lucio Fontana's white series.
The walls of the living room and library were bedecked with 18th and 19th-century art, inspired by the Frick Collection - a U.S institution known for its array of Old Masters and European sculpture and decorative arts.
Another living room is decorated with lithographs made by order of Napoleon.
"We buy what we like. Favourite works are exhibited in the rooms which we visit more often," said Aleksandra.
Rise of "Serbian Angelina Jolie"
Aleksandra started her modelling career in Serbia when she was 15. At 17 she became a member of girl band Models, Serbia's answers to the Spice Girls. One Models hit was called Money, Money with the lyrics: "Money money money I love only money . . ."
Her Serbian father was an architect and Croatian mother an artist. She started school at the Mathematical High School, in Belgrade, and later studied at the city's Faculty of International Management.
Multi-lingual, she speaks English, Spanish and Italian as well as Serbian and Russian and has been nicknamed the Serbian Angelina Jolie.
Stars sang at the £3m wedding
The couple met in the South of France when Aleksandra was 28, and Andrey 33 and married there two years later in a £3million, three-day extravaganza.
Whitney Houston, Christina Aguilera and Enrique Iglesias were flown in to perform at the celebration, at an estimated cost of £1million. A replica of an ancient Russian chapel was erected for their wedding ceremony and jets and rooms in a five-star hotel were booked for 300 guests.
The bride wore a stunning strapless Vera Wang number, food was prepared by the renowned chef Alain Ducasse and the couple went off to honeymoon on the Red Sea.
Socialising with the celebrities
For a scrupulously private billionaire - he hates the term oligarch - it seems only appropriate that among Andrey's wealthy friends is that other intensely private billionaire Roman Abramovich. As a couple, the Melnichenko's love to entertain. Demi Moore and Ashton Kutcher (before their split) were guests on Motor Yacht A for one particular New Year's celebration in glossy St Bart's.
Other celebrity pals include a string of fashion designers and Eva Cavalli, wife of Italian designer Roberto Cavalli.
The couple also move in similar circles to Prince Andrew, and Aleksandra has been pictured with both his ex-girlfriend Caroline Stanbury and his friend Goga Ashkenazi, the Kazhak billionaire who is said to have brokered a controversial deal to sell his Sunningdale mansion for £15million.
For her 38th birthday earlier this year Aleksandra celebrated in Las Vegas (flying in on her private jet) with female friends including Demi Moore and Caroline Stanbury. The night ended at a show by Australian male strip act - Thunder from Down Under.
J-Lo was £1m party act
Since their wedding in 2005, they have hosted a string of glossy parties, with a list of star performers that would fill a festival line-up.
"The boat [Motor Yacht A] is perfect for parties, and we are always looking forward to the next one," Aleksandra told Harper's Bazaar.
It was the setting for a party to mark the couple's third wedding anniversary in 2008, with music courtesy of Lenny Kravitz.
Three years later rapper Snoop Dogg entertained partygoers in a specially built mirrored disco room while Aleksandra partied in an open-backed Azzedine Alaia dress - she changed for the evening from a lime green Givenchy mermaid gown.
For his wife's 30th birthday, Andrey spent £1 million flying Jennifer Lopez from the U.S to perform at his Ascot estate - £600,000 for the performance and a further £400,000 to put her entourage up in top hotels. And last year singers Cher and Kylie Minogue are understood to have performed at a party in glitzy St Moritz, Switzerland to mark the couple's 10th wedding anniversary.
Can't Get You Out of My Head, Love At First Sight and Wow were on the couple's set list.
"Three hundred days a year I wear jeans and a white T-shirt," Aleksandra Melnichenko once claimed.
But she more than makes up for it on the other 65 days of the year. The former model's first high-fashion indulgence was an emerald green Versace number for her school prom when she was 14. On her 30th birthday, she wore a Japanese-inspired Dior by John Galliano gown that weighed more than 80 lb.
Hardly surprising then that she says her personal style is either minimalist or "totally over-the-top". Her wardrobe is packed with pieces by Azzedine Alaia (he calls her one of his "daughters"), she loves Givenchy and Lacroix and is a regular at the annual couture shows.
She considers herself something of a couture curator and readily admits to purchasing clothing that she will never wear, but simply wants to include in her collection.
"Fashion is the most accessible art form," she says, "and it gives us the possibility to create our own art by wearing it."
Multi-million law suits
There's nothing like a bit of super-rich litigation.
Andrey complained that the finish on the paintwork of Motor Yacht A looked cloudy and that paint appeared to be running and sued Azko Nobel, the owner of Dulux, for £62 million, claiming he had to redecorate at a cost of £15 million, as well as fork out £2.5 million a month for a replacement vessel.
The case is understood to have been settled out of court.
In 2013 they sued over a £423,000 sculpture by Polish artist Igor Mitoraj, claiming it was almost half the height of the promised 7ft. The case against the dealer who sold them the work was settled, according to legal documents.
Earlier this year Aleksandra filed a lawsuit against the board of her Central Park home, alleging defects in the building's roof, façade, windows and terrace doors that caused water damage in her penthouse.
Small army of minions
Maintaining a billionaire lifestyle wouldn't be possible without an army of helpers.
Their yacht has a crew of 37 including chefs, deckhands, engineers, and a special team to take care of watersports - all wear Starck-designed uniforms.
Their new sailing yacht is expected to have an even larger crew of 54.
On land, the Ascot estate alone employs four housekeepers, two house managers, three security guards and 14 gardening staff, according to a 2008 building permit.
And that isn't counting the minions who tend to Aleksandra's glamorous looks.