English: A picture of a square rigged ship I shot at Ostend, Belgium during the "Oostende Voor Anker"-event (28-30 May 2010). The picture clearly shows that the yards of the vessel move with the wind. This allows the yards to direct themselves better to the wind, and thus increase efficiency of the sails. Note that besides yards, there are also other rigging arrangements that allow the sails to move autonomously depending on the winddirection. An example is the rigging used at the Reaper ship.