Earlier this year, Richard Branson unveiled his new submarine, the Necker Nymph, also designed and built by Hawkes.

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For instance, Necker, a gorgeous place that is considered the gold standard of private islands, has just 8 guest rooms.

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Winslet and RocknRoll were at Sir Richard's Caribbean retreat Necker Island in 2011 when a fire devastated the Virgin boss's luxury home.

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British billionaire Richard Branson owns Necker Island in the Caribbean.

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After the first solo pilot tests the sub, Mr. Branson himself will pilot it to the bottom of the Puerto Rico Trench, near his private island of Necker in the British Virgin Islands.

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Ever since Sir Richard Branson opened his Necker Island resort in the British Virgin Islands in the early 80s, private islands have been the sexiest vacation choices for the really rich, and they have proliferated around the globe.

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