The SkySails propulsion system consists of a large kite, an electronic control system for the kite and an automatic system to retract the kite. The system bears similarities to kitesurfing. After tests on the Baltic Sea, the first commercial installation is planned for January 2008. The kites, which have an area of around 320 m2, can be flown at altitudes of 100 to 300 meters. Because of the stronger winds at these heights, they receive a substantially higher thrust per unit area than conventional mast-mounted sails. A ship equipped with the current SkySails could consume from 10 to 35% less oil. The SkySail-system is easily implementable on all large vessels. A conventional ship with a SkySail-system has two propulsion methods, making it a type of hybrid vehicle.