Boats

 A small portfolio of boats in the harbor of Urk NL.  If you look at the sailing boats , most have a large wooden device on the sides.  They are Leeboards.  Leeboards are an old school way to control the sideways  force of the wind against the sails.  These older shallow draft boats don't have a center board, so they deploy the leeboard on the lee side of the ship to help keep the ship from moving sideways.