Jeff Bezos will soon be the owner of a $500 million newly-constructed mega yacht from Oceanco, a custom ship builder based in the Netherlands. Although details are sparse, the yacht, called the Y721, is supposed to be 417 feet long (127 meters), have several decks, feature three gigantic black masts, and be the world’s largest sailing yacht when completed.

The Y721 is so large that its three masts will not be able to pass through De Hef, the iconic Dutch bridge, on its way out of the harbor to the ocean, even though the bridge’s center can raise and allow most vessels safe passage. Its height also makes it unsafe for a helicopter to land, so Bezos has commissioned a support yacht with a helipad to travel alongside Y721.

Oceanco based the luxury cruiser’s blueprint on its award-winning, sustainable Black Pearl Yacht, which is one of the largest and most eco-friendly sailing yachts in the world and can cross the Atlantic without burning any fossil fuel. It features technology such as DynaRig carbon masts, solar power, a hybrid-propulsion system, and a waste-heat recovery system.