Jackline

"'A jackline is a rope or wire strung from a ship's bow to stern to which a safety harness can be clipped, allowing a crewmember to move about the deck safely when there is risk of falling or being swept overboard. At sea, falling [Man_oy on sailboats heading offshore, they may be left in place all the time and used as necessary. They are usually attached to strong padeye or cleat fittings at both ends of the boat, allowing the crewmember to move fore and aft by sliding their harness' clip along the line. Jacklines may be made of wire or low-stretch rope. More recently, sailors are using high strength nylon webbing. The reason is that flat webbing does not roll under foot while working on deck. This reduces the hazard that can be created by using rope. The image to the right shows the traditional steel wire jackline and the image below shows an example of a more modern jackline made of flat nylon webbing.