Printable reference
Sails & rigging quick sheet
Sail corners and edges, the cruising sail wardrobe, every trim control, and the rigging that holds the mast up.
Teaching values, not specifications. Wind ranges, trim percentages, and material choices on this sheet are typical teaching values — every boat, rig, and sail differs. Learn the names and the direction of each effect, then calibrate the numbers on your own boat.
Corners and edges of a sail
Head
The top corner of the sail — the corner the halyard hoists, between the luff and the leech.
Tack
The forward lower corner of the sail, between luff and foot, made fast to the boat or spar.
Clew
The aft lower corner of the sail, between leech and foot — the corner the sheets or outhaul pull on.
Luff
The leading edge of the sail, from head to tack — set against the mast or the forestay.
Leech
The trailing edge of the sail, from head to clew — the free edge where twist and stall show up.
Foot
The bottom edge of the sail, running from tack to clew.
The sail wardrobe
Mainsail
The boat's primary working sail, set on the mast and boom — flown on every point of sail, trimmed constantly, and shortened by reefing rather than swapped for another sail.
Jib
A non-overlapping headsail — its clew stays forward of the mast and shrouds — the everyday headsail on modern fractional-rig boats and the change-down sail in a masthead cruiser's inventory.
Genoa
An overlapping headsail — its luff perpendicular exceeds 100% of J, carrying the clew aft past the mast — the light-to-moderate-air workhorse of masthead cruising yachts.
Symmetric spinnaker
A full-bellied downwind sail of mirror-image halves, flown free from a pole that squares it out to windward — the sail that lets a boat run dead downwind.
Asymmetric spinnaker
A downwind sail with distinct tack and clew, tacked to the bow or bowsprit and gybed like a big genoa — widely sold as a gennaker or cruising chute, terms commonly (though not universally) used interchangeably.
Code zero
A flat, genoa-like flying sail for light-air close and beam reaching — cut with just enough mid-girth to measure as a spinnaker under racing rules.
Storm jib
A tiny, high-visibility heavy-weather headsail built to keep the boat driving and steering in a full gale — its size capped by formula under World Sailing OSR 4.26–4.27.
Storm trysail
A small, boomless storm sail set in place of the mainsail and sheeted independently of the boom — sized by formula on P × E under World Sailing OSR 4.26–4.27.
Sail controls at a glance
| Control | Acts on | Effect |
|---|---|---|
| Halyard | Hoists the sail and, once cleated or locked off, sets the base tension along the sail's luff. | More luff tension pulls the draft — the deepest point of the sail's curve — forward and flattens the entry; less tension lets the draft drift aft. As the wind builds it blows the draft aft, so more halyard brings it back where it belongs. |
| Topping lift & lazy jacks | The topping lift carries the boom's weight from the masthead when the sail is not doing so; lazy jacks form a cradle of light lines that guides the falling sail onto the boom. | By design, none on sail shape — and that is the trap: a topping lift left tight while sailing lifts the boom and distorts the leech, so once the sail is drawing it must hang slack. Lazy jacks likewise only guide cloth; they are never the boom's support. |
| Mainsheet | Hauls the boom down and inboard through a multi-part tackle, shortening the distance from the sail's head to its clew and tensioning the leech. | Two modes. Close-hauled, the sheet pulls mostly downward: trimming closes the leech and removes twist, easing lets the top of the sail fall open. Once the boom is eased out, the pull turns mostly horizontal, so the sheet stops controlling the leech and simply sets the sail's angle to the wind — the vang takes over the twist. |
| Traveler | Slides the mainsheet's attachment point sideways along a track across the boat, carrying the whole boom to windward or leeward. | Changes the mainsail's angle of attack while sheet tension — and therefore twist — stays essentially the same. That separation is the whole point: power changes, the leech does not. (It is a first-order model: strictly exact only while the sheet still pulls near-vertically, but it is the right way to think about it.) |
| Boom vang (kicker) | Pulls the boom down toward the mast step from a point partway along its length, tensioning the mainsail's leech independently of the mainsheet. | Off the wind it is the twist control: with the sheet eased the boom wants to rise and the top of the sail to fall open, and the vang is what stops it. Upwind it adds leech tension on dinghies and in a breeze; on a cruising keelboat upwind in light-to-moderate air it usually just sits snug while the mainsheet does the leech work. |
| Outhaul | Pulls the mainsail's clew aft along the boom, tensioning the foot of the sail. | Foot tension shows up mostly in the lower third of the sail: haul the outhaul tight and the lower sail flattens and depowers; ease it and the foot rounds into a deeper, more powerful curve. |
| Cunningham | Hauls down on a reinforced eye a short way up the mainsail's luff, tensioning the luff below the halyard's lock-off. | Exactly what extra halyard would do: luff tension pulls the draft forward and flattens the sail's entry. As the breeze builds and blows the draft aft, the cunningham brings it back — a typical mainsail target is draft about 45–50% aft of the luff, though the number is a guide, not a spec. |
| Adjustable backstay | Tensions the stay running from the top of the mast to the stern, compressing and bending the mast and loading the forestay. | Rig-dependent, and worth learning both ways. On a fractional rig the dominant effect is mast bend, mostly in the upper half to third of the spar: bend pulls cloth toward the luff and leech, flattening the mainsail and opening its upper leech. On a masthead rig the dominant effect is forestay tension: less sag to leeward, so the genoa flies flatter with a finer entry and the boat points higher. |
| Jib sheets | Pulls the headsail's clew aft and inboard toward its fairlead car; only the leeward (working) sheet is loaded at a time, the windward one lying lazy. | In and out sets the headsail's angle of attack. Close-hauled it also closes or opens the leech, because the sheet loads both foot and leech through the clew. |
| Jib fairlead cars | Moves the sheet's turning point fore and aft along a deck track, changing the angle at which the sheet pulls on the clew. | Car aft: the sheet pulls more along the foot, so the foot flattens while the upper leech opens and twist increases — the depowering setup. Car forward: the sheet pulls down harder, closing the leech, reducing twist, and deepening the foot — power for light air and chop. |
| Furling line | Rotates the drum at the base of the forestay foil, winding the sail around the stay as the line is hauled and letting it unwind as the sheet pulls the sail out. | Counter-intuitive but important: partially furling a genoa makes it fuller, not flatter. Rolling the sail concentrates its built-in camber, so a part-furled genoa sets baggy and draft-aft exactly when you want it flat. Foam or rope luff pads are built into some sails specifically to soak up that extra cloth mid-luff. |
| Spinnaker pole | Braces the guy — and with it the sail's windward corner — out from the mast, held up by its own topping lift and down against skying by its downhaul (called the foreguy on bigger boats). | Positions the spinnaker's tack in space. Squaring the pole aft rotates the sail around to windward for deep angles; easing it forward lets the sail fly further ahead for hotter angles. Pole height sets luff tension so the two lower corners fly level. |
| Spinnaker guy & sheet | The guy runs from the windward corner through the pole's outboard jaw and hauls the pole aft or eases it forward; the sheet leads to the leeward clew and trims the sail in and out. | The guy sets how far the sail is rotated around the boat, via the pole; the sheet sets the sail's angle of attack and how close the luff is to curling. Either lower corner can be tack or clew: on the gybe the two lines simply swap roles. |
| Tack line | Pulls the asymmetric spinnaker's tack down toward the end of the bowsprit or the stem fitting, tensioning the sail's luff. | Hauled tight it gives a straight, stable luff for reaching and for breeze. Eased — a foot or two is typical, boat-dependent — on broad angles, it lets the whole sail rotate out to windward into cleaner air ahead of the mainsail. |
Standing vs running rigging
Standing — holds the mast up
- Forestay — 1×19 stainless-steel wire on most cruising yachts — the stiffest, lowest-stretch wire construction. Insurers commonly suggest replacing wire standing rigging every 10–15 years or so; treat that as guidance, not law, and inspect for broken strands and corrosion at the terminals.
- Backstay — 1×19 stainless wire, often with a mechanical or hydraulic tensioner at its lower end on performance-minded boats.
- Cap shrouds — 1×19 stainless wire on most cruising yachts; rod rigging on many racing and larger performance boats — lower stretch and longer fatigue life, but harder to inspect and repair.
- Lower shrouds — 1×19 stainless wire, sized together with the rest of the rig.
- Spreaders — Rigid struts fixed to the mast — part of the spar rather than the wire rigging around them.
- Chainplates — Metal straps or fittings — typically stainless steel — bolted to the hull, the deck, or an internal structural member.
- Turnbuckles — Threaded stainless-steel fitting. US usage says turnbuckle; UK usage calls the same fitting a bottlescrew or rigging screw.
- Inner forestay — 1×19 stainless wire, like the boat's other stays.
Running — works the sails
- Main halyard — Double braid — plain polyester on many cruisers, or a Dyneema (HMPE) core under a polyester cover where halyard stretch must be minimal.
- Jib halyard — Polyester double braid, or Dyneema-core where lower stretch is wanted.
- Spinnaker halyard — Polyester double braid, or commonly Dyneema-core on performance boats for minimal stretch under a big, pulling sail.
- Mainsheet — Quality polyester double braid — hauled and eased constantly, so an easy grip matters as much as low stretch.
- Jib sheets — Polyester double braid — low stretch, grippy on a winch drum, and unbothered by UV, which is why it is the default sheet material on cruising boats.
- Boom vang — Polyester double braid on the tackle; rigid vangs add a gas or spring strut that pushes the boom up.
- Reef lines — Low-stretch polyester double braid; single-line systems work far better with low-friction blocks at the cringles.
- Furling line — Polyester double braid.
- Topping lift — Polyester double braid; its loads are light next to halyards and sheets.
Rope constructions at a glance
| Rope | Stretch | Floats | Used for |
|---|---|---|---|
| Three-strand laid | High | No | Anchor rode, mooring and dock lines |
| Double braid (polyester) | Low | No | Sheets and all-round running rigging |
| Dyneema-core double braid | Low | No | Halyards and highly loaded control lines |
| Single braid | Low | Yes | Soft shackles and strops, dinghy sheets, floating heaving lines |
| Anchor plait (8-plait) | High | No | Anchor rode that stows flat and resists kinking |
Learning aid only — not for navigation. Confirm current rules and local requirements with the relevant authority.