An epic party yacht sunk in the U.K. before it even set ... Built by a Dutch shipyard, Oceandiva cost a hefty £25 million (about $31 million) to come to fruition, according to Smart Group.

Lauren Sánchez's relaxing sunbathing session aboard her fiancé Jeff Bezos' $500 million yacht, Koru, was interrupted by customs officers conducting a surprise inspection on New Year's Eve.

Most people who own multi-million-dollar yachts choose to enjoy them privately during certain times of the year and use it as a charter yacht for the remaining time, but that's hardly an investment.

The U.S. has spent tens of millions of dollars over more than two years maintaining a $230 million mega-yacht it seized as part of efforts to crack down on oligarchs linked to Russian President ...