LOS ANGELES (CBS) — Yachts, by definition, are supposed to be luxurious, but one docked near Venice goes above and beyond mere luxury.

A yacht named “Serene” was spotted by Sky 9 Wednesday night – all 440 feet of it. The super yacht comes with seven decks and almost 50,000 square feet of interior space, 12 staterooms, two helicopter landing platforms, a salt water pool and storage for a submarine.

(Most watercraft with those kinds of amenities usually go by other names, like “cruise ship” or “aircraft carrier.” Just sayin’.)

“Serene,” which is estimated to be worth $300 million, is listed as the 9th largest yacht in the world by SuperYachts.com, just after David Geffen’s “Rising Sun” which measures in at 454 feet.

She’s rumored to be owned by a Russian vodka tycoon.