Octopus can accommodate 26 guests in 13 cabins, many of which are suites. Her crew of 63 is spread out in 30 cabins. Just as a reference here, at full load, she has a crew to guest ratio of nearly 2.5 crewmen per guest. For comparison, the crew to guest ratio on Royal Caribbean’s Anthem Of The Seas has a ratio of .31 crewmen to each guest. The Seaborne cruise line’s super up-market and small-sized ship fleet, like the Seaborne Odyssey, has about a .73 crewmen per guest ratio. Of course, during parties, the vessel can accommodate hundreds of people temporarily.

Octopus has an incredibly classy exterior design that is somewhat timeless when compared to more exotic and bland looking yachts that sail the high seas these days. This is in part due to its purpose—it is both a pleasure yacht and an exploration vessel.

The utilitarian half of Octopus’s personality shows through in her overall design. Case in point, her large floodable well-deck in her stern that holds a yellow submarine named Pagoo. Pagoo can embark ten people on up to eight-hour-long underwater adventures. The sub can dive as deep as 1,000 feet. ISE Ltd. built the submarine, which has huge glass portholes for its occupants to gawk out of, for Allen.

An unmanned remotely operated vehicle that can dive far deeper—thousands of feet below the surface of the ocean—is also stored and deployed from here along with the ship’s primary tender, Man Of War.

Allen’s obsession with aviation also injected some warship-like qualities into Octopus. She has two landing pads—one on the bow and a very large one on the stern. The stern pad is co-located with a huge helicopter hangar capable of easily storing two helicopters—Allen’s Sikorsky S-76C and his MD-902 NOTAR Explorer. Such a large hangar bay—or just any hangar bay at all—is quite unique even in the mega yacht universe.

It found the USS Lexington at the bottom of the Coral Sea and the USS Indianapolis as well as the Japanese battleship Musashi near the Philippines. It even recovered the ship’s bell from the sunken HMS Hood. She has also executed Arctic and Antarctic expeditions with the help of her hardy steel hull that is Ice Class 1A rated, including traversing the Northwest Passage.

But it’s not as if Octopus is all business and no play, far from it in fact. The primary purpose of the vessel is still to entertain its guests like nothing else can. Seattle’s Jonathan Quinn Barnett designed its interior, which carries over its exterior’s blending of classical nautical design cues with a modern flare. The vessel is equipped with a large pool that can be converted into a dance floor via a retractable glass system and is replete with a top-of-the-line lighting system. You can see Octopus in party mode in this photo and this series of photos.

She also features an absolutely top-notch recording studio—another one of Allen’s great loves was music. Many hitmakers have recorded in the sea-borne studio, such as Mickjagger, Usher, Johnny Cash, Bono, and god knows who else, but rest assured the secret list is extremely impressive. Of her eight decks, one is entirely dedicated to the owner alone. It features a private entertaining lounge with a full bar, its own jacuzzi, and dining area, as well as its own dedicated elevator, one of two on the entire ship.

A library, bar, movie theater, gym, observation lounge, and a complete dive center—with its own hyperbaric chamber—are all available to guests. The rear landing pad doubles as a basketball court, which makes sense as Allen owned the Portland Trailblazers. The list of accouterments goes on and on. It even has a glass-bottom viewing area!

The best collection of photos showing off Octopus’s endless features are in the videos posted below:

When it comes to its power-plant, Allen spared no expense. The ship runs off a diesel-electric arrangement with eight diesel generators powering two electric motors that provide six megawatts of juice to drive her screws. It’s supposed to be remarkably efficient, giving the ship the ability to cruise a whopping 12,500 miles at 12.5 knots on a single tank of gas and hit a top speed of 19 knots.

Paul Allen described his passion and amazement for the project in his 2011 autobiography, according to Bloomberg, stating:

Overall, even though Octopus is 16 years old, it remains one of, if not the top yacht in the world. Not in size, but in quality, thoughtfulness of its design, timelessness, features, quality of construction, and especially versatility. In fact, from what I can tell, its selling price is substantially more than what Allen paid for the vessel in 2003. This is a very rare reality in the world of large vessels where depreciation driven by a tiny customer base can be absolutely brutal.

You need extremely deep pockets not just to buy Octopus, but to keep it running. The rule of thumb is that a yacht costs roughly ten percent of its total cost to operate annually. So in this case, at least according to the sale price, we are talking $32.5M every year. But that number is probably even higher considering all the unique toys embarked aboard her and the specialized crew needed to maintain and operate them.

Security is a big part of this. A mega yacht is a huge and slow target literally floating on the water. Considering the wealth and notoriety of the owners of these types of vessels and their guests, enemies and nefarious opportunists are not hard to come by. With this in mind, a highly-trained security team is needed to stand round-the-clock vigil. There have been many reports that Allen had a team of ex-Navy SEALS on-board to protect Octopus. I have no idea how accurate that often repeated rumor is, but would you be surprised if he didn’t seek the most talented operators with vast experience in the maritime operating environment to protect his pride and joy? I mean, when you own something this expensive already, why not?

So, for the richest human beings on the planet, a ‘for sale’ Octopus represents a very rare opportunity to snap up a vessel that has stood the test of time when it comes to the hardest to impress community in the world. And a ship that is uniquely capable of grand discoveries and adventure, as well as throwing unrivaled parties on the French Riviera. In fact, Octopus is still arguably the best design that can actually wear both hats, with other exploration-capable yachts looking far less glamorous and luxurious.