Launched in 2003 at a cost of $200 million,[1] Octopus is a private vessel that has been loaned out for exploration projects, scientific research and rescue missions.

[2] Octopus's exterior was designed by Espen Øino Naval Architects and built by the German shipbuilders Lürssen in Bremen and Howaldtswerke-Deutsche Werft in Kiel.

The yacht also has a pool, located aft on one of its upper decks,[5] and two submarines (one of them operated by remote control and capable of attaining greater depths).

These include assisting in a hunt for an American pilot and two officers whose plane disappeared off Palau, and loaning his yacht to scientists to study the coelacanth, a "living fossil" that was once believed to be extinct.

HMS Hood was hit by a shell from the German battleship Bismarck; its magazines exploded and the ship sank in minutes with a loss of over 1,400 lives.

[8] In March 2015, an Allen-led research team announced that it had found the Japanese battleship Musashi in the Sibuyan Sea off the coast of the Philippines.