Japanese sailor Kenichi Horie set sail from Hawaii, the US, to Japan on a wave-powered boat on March 16. The three-tonne boat, called Suntory Mermaid II, is made of recycled aluminium and relies on the energy of waves to move the two fins at its bow and propel it forward. The vessel is equipped with an engine and a sail mast for emergencies. Kenichi describes the boat as a sturdy vessel. He will travel 6,400 km, which is expected to take him 70 days. A diesel-powered boat can cover the distance in 10 days.