Largest Yacht Ever Built in Italy Knocks Paul Allen Off the Top 10

Billionaire Microsoft co-founder Paul Allen no longer owns one of the world's 10 largest yachts thanks to the just-launched Serene (above) from Fincantieri. At just under 440 ft. Serene is the largest yacht ever built in Italy, and enters the list of the world's largest yachts at No. 9, according to Camper & Nicholsons – just behind the floating brothel Savarona. That knocks Allen's famed 414-ft. Octopus out of the top 10 altogether (No. 1 of course is still, by a mere 18 inches, Roman Abramovich's Eclipse). The billionaire buyer of Serene is unknown. Designed by Espen Oeino, the Serene, which took four years to complete, has seven decks, a tender hangar and two helipads. The high-tech megayacht features a large seawater swimming pool and a submarine with a diving depth of up to 100 metres. The 4,500 square meter interior boasts super-luxe accommodations and entertaining spaces designed by Pascale Reymond of London's Reymond Langton Design.

Billionaires Demand Military-Grade Security on Their Superyachts

In an effort to boost the flagging superyacht market, manufacturers are fitting them out with increasingly complex, military-grade security systems aimed at assuaging the fears of paranoid billionaires. Bloomberg News reports from the Monaco Yacht Show that security systems similar to the ones on Roman Abramovich's enormous Eclipse are now standard issue for high-end craft. Pascal Wiscour-Conter, chief executive officer of Equisea Yacht Management in Monte Carlo, says that any billionaire buying a superyacht these days shells out an extra $400,000 at least for additional defensive measures, including bulletproof glass and "NATO military technology integrated with NASA satellite tracking to create an invisible offensive security bubble with underwater sonic cannons and surface lasers that evaluate and take out anyone who lays siege to the vessel." Wiscour-Conter notes that the high-tech system "knows the difference between a malicious scuba diver and a curious dolphin, and we transmit all the information to your iPhone four times a day."