Safety kit
What Is a Jackstay on a Sailing Boat? Uses and Rigging
Published · Last checked October 2026
A jackstay is a strong length of flat webbing, wire or rope run along the deck of a yacht, usually from the cockpit to the bow on each side. Crew clip their harness tether to it so they can move along the deck while staying attached to the boat. Jackstays are used at night, in rough weather and whenever the skipper decides, and should be rigged so a clipped-on person cannot fall over the side.
What jackstays are for
The safest way to deal with man overboard is not to go overboard at all. A lifejacket keeps you afloat once you are in the water; a harness and tether clipped to a jackstay aims to keep you on the boat. On a dark, rough night, a person in the water is very hard to find, so staying attached matters.
Types of jackstay
| Type | Pros | Cons |
|---|---|---|
| Flat webbing | Does not roll underfoot; most common | Degrades in UV; replace every few seasons |
| Stainless wire | Strong, long-lasting | Rolls underfoot like a marble; can be noisy |
| Dyneema rope | Light, very strong | Can roll; also UV sensitive |
How to rig a jackstay
- Run it from a strong point near the cockpit to a strong point near the bow, on each side or down the centreline.
- Attach to through-bolted fittings such as cleats or dedicated eyes, not stanchion bases or guardrails.
- Keep it taut, and ideally inboard, so a person clipped on cannot slide over the side.
- Fit a cockpit strong point so crew can clip on before they leave the companionway.
When to clip on
Most skippers set clear rules: always at night, in fog, in rough weather, when sailing alone on watch, and whenever going forward to reef or handle sails. Wear an automatic lifejacket with an integral harness and crotch straps. Check webbing jackstays for UV damage and fraying each season. The personal safety lesson and Day Skipper safety equipment lesson cover harness use.