Length: 190 ft.
Designed by: Ron Holland; Pieter Beeldsnijder interiors
Sun Microsystems co-founder and Silicon Valley venture capitalist Bill Joy paid $50 million for this hybrid superyacht, which was launched last October and deemed the most eco-friendly and energy-efficient boat afloat, setting a new standard for green luxury. Built by the same design team as the Juliet, the Ethereal was the first boat of its size to employ lithium polymer batteries, which are recharged by the boat's propulsion system while sailing. The luxury ketch houses guests in four cabins, and the owner's suite includes an office, Jacuzzi, and sauna.