When you have a fortune of billions, having the latest sports car or the largest house is child's play.
For the likes of Roman Abramovich and the Sheikhs of the UAE, the real way to demonstrate one's financial worth is to have the grandest yacht.
And while size most definitely matters (no self-respecting tycoon would have a vessel less than 200ft), the mod-cons are no less impressive, with helicopter landing pads and even missile detection systems.
Size matters: The Eclipse, owned by Roman Abramovich, is the world's largest yacht at 557ft. Pictured last month off the coast of Cannes, it boasts twin helicopter pads and its own missile detection system
The largest, and most famous, is of course Mr Abramovich's $500million Eclipse, which, at 557ft, is the world's largest boat.
It requires a team of 70 to run and comes complete with the aforementioned radar equipment and twin helicopter pads, as well as bullet-proof windows and armour plating on the bridge.
It even has its own submarine, which can dive to 160ft, and, in keeping with the safety-first theme, also functions as an escape pod.
Competitive: Sheikh Mohammed bin Rashid al-Maktoum's 531ft Dubai yacht had been the world's largest prior to the Eclipse's launch. It is believed to have cost over $300million when it launched in 2006
Steeped in history: Egypt's 478ft El Horriya, which is the world's fift's largest boat, is a former presidential yacht. Built in 1865, it was the first vessel to sail through the Suez Canal. It is now owned by the country's navy
The yacht joins a fleet owned by the oligarch, which includes the 377ft Pelorus, 282ft Ecstasea and 160ft Sussurro.
Its launch in 2009 caused outrage among fellow megayacht owners, who regularly compete to own the largest boat. It is believed to have particularly incensed UAE Prime Minister Sheikh Mohammed bin Rashid al-Maktoum, whose 531ft Dubai yacht had been the world's largest prior to the Eclipse's launch.
It was said to have cost over $300million when it launched in 2006 and is thought to have a full-sized cinema, squash court, gym, a helicopter pad, and a storage area for a submarine.
Megayacht wars: Roman Abramovich (left), UAE Prime Minister Sheikh Mohammed Bin Rashid Al Maktoum (centre) and Saudi Arabia's Crown Prince Sultan Bin Abdulaziz Al-Saud (right)
Sheikh Mohammed is now said to be building an even larger vessel to rival Mr Abramovich's.
They are by no means the only megayacht owners. The Sultan of Oman launched the Al Said in 2008, a vast 508ft vessel that can reportedly host a crew of 154, 70 guests and a 50-piece orchestra.
And according to Newsweek, Saudi Crown Prince Sultan bin Abdulaziz requires a crew of 96 on his 457ft Al Salamah boat - a mere little sister to the family's other boat, the 482ft Prince Abdulaziz - while Sheikh Hamad bin Khalifa al-Thani, the Emir of Qatar, spends his free time aboard the 436ft Al-Mirqab.
Retreat: Sheikh Hamad bin Khalifa al-Thani, the Emir of Qatar, spends his free time aboard the 436ft Al-Mirqab
Luxurious: The British-owned Enigma, is relatively small at just 224ft. It is easily identifiable for its convex windows and has its own basketball court. It usually docks in Sardinia, but is also regularly spotted in Mallorca
Egypt's 478ft El Horriya, which ranks fifth in a list of the world's largest boats, is steeped in history. The former presidential yacht, it was built in 1865 and was the first vessel to sail through the Suez Canal. It is now owned by the country's navy.
The Republic of Turkey's Savarona is equally impressive. At 442ft, it was ahead of its time when it was built in 1931 and boasts a spectacular staircase. Much of it was destroyed by a fire in 1979, but it was carefully restored over the following 13 years and continues to sail.
Billionaire boat-owners: Microsoft co-founder Paul Allen (left), David Geffen (centre) and Aidan Barclay (right)
A-listers, of course, will be more familiar with Paul Allen's Octopus, which, like the Eclipse, docks at Cannes for the annual film festival. Among the guests the Microsoft co-founder hosted this year were Bar Refaeli, Jane Fonda, Jodie Foster and Ryan Gosling.
THE WORLD'S TOP TEN BIGGEST SUPERYACHTS
- Eclipse (557ft) - owned by Russian oligarch Roman Abramovich
- Dubai (531ft) - owned by UAE Prime Minister Sheikh Mohammed bin Rashid al-Maktoum
- Al Said (508ft) - owned by the Sultan of Oman
- Prince Abdulaziz (482ft) - owned by the Saudi Royal Family
- El Horriya (478ft) - owned by the Egyptian Navy
- Al Salamah (457ft) - owned by Saudi Crown Prince Sultan bin Abdulaziz
- Rising Sun (452ft) - owned by American media tycoon David Geffen
- Savarona (442ft) - owned by the Republic of Turkey
- Serene (439ft) - owner unknown
- Al Mirqab (436ft) - owned by Emir of Qatar, Sheikh Hamad bin Khalifa al-Thani
The 414ft cruiser, which requires a crew of 60 to run, may be smaller than the Eclipse, but is by no means less well-equipped, with two helicopters, seven boats, a submarine, and a remote controlled vehicle that crawls the ocean floor.
But its reign as the most lavish U.S.-owned yacht was short-lived. Media tycoon David Geffen's 452ft Rising Sun yacht is rumoured to have been commissioned in 2004 specifically to be larger than the Octopus.
Prior to the launch of Octopus, Limitless, owned by Limited Brands' CEO Lex Wexner, was the largest boat that sailed with a U.S. flag. The Victoria's Secret owner regularly takes his 315ft yacht across the Atlantic to the island of Mallorca in Spain.
Little is known about the Limitless, which was built in 1997, as Mr Wexner has never permitted allowed interior photography of the vessel.
The Atlantis II, which was built by the late Stavros Niarchos, is another celebrity magnet. The Greek shipping tycoon's grandson, Stavros Niarchos III, has dated some of the world's most famous women including Paris Hilton and Mary-Kate Olsen.
The 397ft yacht was built in 1981 and is now used by the Niarchos family.
The British-owned Enigma, is relatively small fry in contrast. But the 224ft yacht, owned by Ritz chairman and publishing heir Aidan Barclay is still considered one of the world's most luxurious superyachts.
It is easily identifiable for its convex windows and has its own basketball court. It is usually docked in Sardinia, but is also regularly spotted in Mallorca.
