Never underestimate how hard the rich will fight over beachfront property.

That’s one takeaway from litigation now unfolding in Manhattan, California and the Bahamas, where two billionaire neighbors are locked in a nasty battle over real estate. Hedge fund founder Louis Bacon wants to stop his Bahamas neighbor Peter Nygard, who owns a Canadian women’s fashion company, from further expanding the shoreline around Nygard’s 150,000-square-foot compound, where he’s known for throwing extravagant parties.