Many cities worldwide that are short of easily available space to expand or construct airports are seriously considering the idea of floating airports.
Probably the most famous planned large scale floating airport was the Tokyo Bay Megafloat project which was cancelled in 1998.
Another floating airport project, Megafloat Phase II, is now being planned for Yokosuka City in Kanagawa Prefecture, Japan. The project will utilize the technical lessons learned during a test floating runway that operated experimentally from 1995 to 2000.
Kansai International Airport in Japan is another airport that is somewhat close to the concept of a floating airport as it is built on an artificial island in the Osaka Bay.
A floating airport 10 miles off the coast of San Diego has been proposed by US-based Ocean Works Development. However, the high cost – $20 billion – of the project has deterred any concrete action on the proposal.