"Venus," the vessel commissioned by Apple's late co-founder Steve Jobs, appears docked on Oct. 29, 2012, at the De Vries shipyard in Aalsmeer, the Netherlands. The cost to build the boat reportedly topped $138 million. Philippe Starck, a Frenchman, helped design the yacht.

This 139-foot yacht, the $15 million "Adastra," launched last year into China's Pearl River. The vessel's shape draws from the trimaran design, which features a main hull and two smaller ones. Adastra's owner, Hong Kong businessman Anto Marden, owns a couple of islands near Indonesia.

Philippe Starck designed the 390-foot "A" to outrun threats: The vessel's high-speed diesel motors propel the boat up to a third faster than other super yachts; its hull shape resembles a knife, which makes boarding the vessel challenging for any potential intruder. This boat belongs to Andrey Melnichenko, a self-made billionaire who owns a 75 percent stake of the largest independent coal producer in Russia.

Owned by hedge fund manager Elena Ambrosiadou, the 289-foot "Maltese Falcon" is one of world's largest privately owned sailboats. American venture capitalist Tom Perkins sold the three-masted clipper, which has 11,000 square feet of living space, in 2009, two years after he reportedly paid at least $150 million to build it.

"Dubai" belongs to the ruler of Dubai, Sheikh Mohammed bin Rashid Al Maktoum. The 531-foot vessel, the world's second largest private yacht, can accommodate a UH-60A Black Hawk helicopter.

Roman Abramovich, a Russian billionaire and the owner of private investment company Millhouse, in 2011 sold the 377-foot "Pelorus" to David Geffen for $300 million. Geffen also owns the 453-foot Rising Sun. Pelorus features two helipads.

Microsoft co-founder Paul Allen's 414-foot "Octopus" appears at anchor on Jan. 31, 2011, in Ushuaia Bay, Argentina. The boat reportedly has 60 permanent crew members, two helicopters and a remote-controlled submarine.

Qaboos bin Said Al Said, the sultan of Oman, owns "Al Said," a 508-foot vessel. The world's third-largest luxury yacht appears docked in Muttrah Harbor, Muscat.

Burgess Yachts currently lists "Ambrosia III," a 213-foot yacht, on sale for $85 million. The boat runs on diesel-electric motors, which typically power large commercial vessels, and accommodates up to 12 guests and 20 crew members.