The Jet, the world's first hydrogen-powered flying boat due to be built in Dubai next year, soars 3ft above the water, powered by two hydrogen fuel cells.
Solar Express, a 427ft superyacht concept from Anthony Glasson of design studio M51, is covered tip to tail with solar panels for cleaner cruising.
U-Boat Worx has updated the design of its three-person Super Sub, an ultra-luxury submersible with a depth rating of 300m and increased top speed of up to 10 knots.
Designed by architects Van Geest Design and naval engineering company Rob Doyle Design, Domus is a 130ft solar-electric trimaran shaped like an ancient Roman house.
The Candela P-12 Shuttle hydrofoil electric ferry is set to be the world's fastest electric ship when it hits Stockholm's waters next year, with a speed of 30 knots.
The Epiphany superyacht from Steve Kozloff Designs boasts its own private submarine and seaplane, and an interior spread across three decks.
View the companion photo galleries for 'Future transport: Land' and 'Future transport: Air'.