Personnel transfer from USS Rankin by highline, a form of jackstay, 1960.

A jackstay is a cable or bar between two points to support and guide a load between those points, or as an anchor to attach something to be constrained along that line. The term is mostly used in a marine context and originated on sailing ships. Note the use of the term 'stay' implies load bearing working rigging. In diving it is also a line to guide the movements of a diver between the endpoints.

Nautical applications

A jackstay between two ships of the Indian navy
Form of jackstay (also called a spanwire) by the US Navy used to support a hose for refuelling at sea

Jackstays are used in several maritime applications. These include:

Diving jackstay

Jackstay search pattern using two fixed jackstays to define the search area and a movable jackstay to guide the divers on each leg of the search
Snagline search pattern using jackstays to define the search area and guide the divers who drag a line between them to snag the target

A diving jackstay is a form of guideline laid between two points to guide the diver during a search or to and from the workplace or to support and guide equipment for transport between two points. A downline is a diving jackstay from an anchor point at or above the surface to the underwater workplace used to control descent, ascent and the transfer of tools, materials and other equipment between the surface and the workplace.[4]


See also


  1. ^ Palmer, Joreph, ed. (1975). Jane's Dictionary of Naval Terms. London: Macdonald and Jane's Limited. ISBN 0 356 08258 X.
  2. ^ a b "Jackstay". Merriam-Webster. Retrieved 16 July 2019.
  3. ^ Purser, Adam; Purser, Debbie. "A Tall Ship Guide from Classic Sailing" (PDF). Retrieved 18 July 2019.
  4. ^ Barsky, Steven M.; Christensen, Robert W. (2004). The Simple Guide to Commercial Diving. Hammerhead Press. pp. 78, 92–93. ISBN 9780967430546.
  5. ^ Larn, Richard; Whistler, Rex (1993). Commercial Diving Manual (3rd ed.). Newton Abbott, UK: David and Charles. ISBN 0-7153-0100-4.
  6. ^ Hanekom, Paul; Truter, Pieter (February 2007). "Section 17: Seabed searches". Diver Training Handbook (3rd ed.). Cape Town, South Africa: Research Diving Unit, University of Cape Town.