Images: The floating city

Powered by solar panels and wave energy, the city would navigate from the east coast of the US across the Atlantic to Europe and into the Mediterranean.

It would loop back and sail around the Cape of Good Hope at the tip of Africa and across to Australia. Heading into East Asia, it would steer across the Pacific before spending the end of the year on the west coast of North America. It would chase the summer sun into South America.

If completed, the city will be 750ft at the beam, 350ft high and 4,500ft in length – more than three times longer than the Queen Mary II cruise ship.