The Largest Privately Owned Yacht - Octopus

Octopus is currently the world's eighth largest superyacht, owned by Paul Allen, the co-founder of Microsoft, to whom she was delivered in 2003. Octopus is the third largest superyacht that is not owned by a head of state, measuring 414 feet (126 m).

Octopus sports two helicopters on the top deck (one in front and one on the back), and a 63-foot (19 m) tender docked in the transom (one of seven aboard). The yacht also has a pool on board, located aft on one of her upper decks, and two submarines: one operated by remote control for studying the bottom of the ocean. Side hatches at the water line form a dock for jet skis.

The exterior was designed by Espen Øino Naval Architects and built by the German shipbuilders Lürssen in Bremen and HDW in Kiel. Her hull is made of steel. The interior was designed by American designer Jonathan Quinn Barnett of Seattle.

Allen also owns Tatoosh, also one of the world's 100 largest yachts.

Source: wikipedia.org