Now a passenger ship operated by the Viking Line has been treated to the Rotor Sail Solution and has set sail on wind-assisted trips between Finland and Sweden.

The M/S Viking Grace – which has 880 cabins and can accommodate 2,800 passengers and around 500 cars – went into service in 2013, when it was reported to be the first ship of its size to be fueled by Liquefied Natural Gas (LNG). Its hull was hydrodynamically-optimized for low fuel consumption and soundproofing technology was fitted to keep noise down. So it already boasted some noteworthy green credentials.

A single Rotor Sail cylinder measuring 24 meters (78 ft) tall and 4 meters (13 ft) in diameter has now been installed on the passenger vessel, which is described as a modern version of the Flettner rotor.