9Eclipse – Around $700 Million

Built by Blohm+Voss and delivered in 2010, Eclipse stretches 162.5 meters and was once the world’s longest private yacht.

The vessel was commissioned for businessman Roman Abramovich and is packed with extravagant amenities. Reported features include two helicopter landing areas, a swimming pool, a cinema and a private submarine.

Its construction cost is generally reported in the region of $590–700 million, although the precise final figure has never been publicly confirmed.