The world's largest and most expensive yacht, owned by Russian billionaire Andrey Melnichenko, was spotted in Turkey's Mediterranean resort town of Marmaris early Sunday.

The deceptively named "Sailing Yacht A", a gigantic 143-meter-long vessel equipped with 100 meter tall carbon fiber sailing masts, is the largest of its kind in the world, according to Boat International.

The yacht has eight floors, an underwater observation room, three pools, gym, garages for four vehicles and a helipad. The underwater observation pod in the keel is surrounded with a shatter proof 30 centimeter thick glass. It is the largest private sail-assisted motor yacht in the world.

The $450 million vessel will need a crew of 54 once it is fully operational with 20 passengers aboard.

The vessel was designed by French designer Philippe Starck, who also produced Steve Jobs' yacht "Venus."

Andrey Melnichenko is a Russian industrialist and philanthropist. With an estimated personal wealth of $13.2 billion, he ranked 89th in the Forbes World's billionaires list and 9th in Russia in 2017.