What does jackstay mean?
A jackstay is a narrow nautical term for the strong support that braces a sailing vessel’s bowsprit against upward movement. Usually a steel wire, chain, or rope, it runs between the bowsprit and the foremast and helps keep the bowsprit correctly positioned. In a working sailboat, a damaged or badly tensioned jackstay can affect the rig’s stability and the set of the sails. Although the word may sound generic, it is specialized nautical vocabulary and is normally left untranslated in technical manuals and yachting discussion. A jackstay is often confused with a forestay, but the jobs are different: the forestay primarily supports the foremast against forward and downward forces, whereas the jackstay restrains the bowsprit’s tendency to lift. Knowing the distinction helps sailors diagnose rigging problems and understand older descriptions of ship construction.
nounA nautical stay or support connecting a sailing vessel's bowsprit to its foremast, used to resist the bowsprit's tendency to rise. It may be made of wire, chain, rope, or, historically, wood or iron.
- A rope, wire, chain, or other support running between the bowsprit and foremast of a sailing vessel to prevent the bowsprit from lifting.
"The rigger replaced the frayed jackstay before the yacht sailed."
"The crew checked the jackstay and its fittings before leaving the marina."
"An old ship survey describes the jackstay as a heavy iron bar supporting the bowsprit."
The standard plural is jackstays. The singular is commonly used attributively in terms such as jackstay chain and jackstay wire.
"The inspection found cracks in two of the jackstays."
A jackstay holds the bowsprit down; a forestay mainly holds the foremast up.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does jackstay come from?
Jackstay is formed from jack and stay. In English nautical usage, a stay is a rope, wire, or other line used to support or restrain part of a vessel’s rig, while jackstay names the particular support that braces the bowsprit. Related terms such as forestay and staysail preserve the older sense of stay as a supporting or restraining line.
How jackstay is actually used
This is specialized nautical terminology rather than general-purpose English. Modern usage commonly refers to wire or chain, while historical accounts may describe rope, timber, or iron supports.
Easily confused with jackstay
A forestay supports the foremast against forward and downward forces, while a jackstay braces the bowsprit against upward movement.