A cargo ship has completed a two week journey using a computer-controlled kite to help tow the ship, saving engine power and fuel.

SkySails, the maker, estimates fuel savings of 10 to 15% during the time the kite was flying, representing a savings of about $1,000 to $1,500 in fuel costs per day. SkySails claims that freight ships and cruise liners could reduce fuel consumption by up to 50% under optimal conditions.