Japanese adventurer Kenichi Horie set out from Hawaii on Sunday hoping to make the first crossing of the Pacific in a wave-powered boat. The 69-year-old left Honolulu at the start of a 4,400-mile journey to Japan in his 9.5m aluminium catamaran Suntory Mermaid II.

The 3-tonne vessel is powered by the kinetic energy captured as the boat pitches over waves – two hydrofoils at the bow perform a motion similar to the tail flukes of whales and dolphins and propel it along. Horie expects it to have a top speed of around 5 knots, and to average around 3 knots. At this speed he expects the trip to take around three and a half months.

Electric power will be provided by solar panels – and the boat has sails and a diesel engine in case of emergencies. Horie does not plan to use them on the trip.

Horie has previously crossed the pacific on a craft made from aluminium beer kegs, and in 1962 he stepped ashore at San Francisco following a 94-day voyage from Japan in a 19-foot sailing boat – and was promptly arrested. On hearing of his voyage, the mayor gave him the key to the city and released him.

You can keep up with his progress here. 

Image: Sherry Vann.