Spinnaker Handling
The spinnaker is the most powerful and most temperamental sail on the boat. Master it and you fly. Mishandle it and you swim.
Symmetric vs Asymmetric Spinnakers
A spinnaker is a large, lightweight downwind sail flown from the masthead (or near it), designed to catch wind that the mainsail and headsail can't use efficiently. There are two fundamental types, and the choice between them affects every aspect of handling.
Symmetric spinnakers are the classic balloon shape — equal on both sides, flown from a spinnaker pole that projects the tack out to windward. They are trimmed with a sheet and a guy (or afterguy), and the pole position is adjusted constantly to match the wind angle. Symmetric kites are most effective on deep downwind angles (broad reach to dead run). They require more crew, more gear (pole, topping lift, foreguy), and more skill to handle.
Asymmetric spinnakers (also called gennakers or A-sails) are shaped more like a giant genoa — with a distinct luff and leech. The tack is fixed to a bowsprit or the bow, and the sail is trimmed with a single sheet. Asymmetrics are simpler to handle (no pole), require fewer crew, and are excellent on reaching angles. They're less effective dead downwind than a symmetric kite but far easier to gybe.
Which is better for racing? It depends on the course. Symmetric spinnakers dominate on windward-leeward courses with deep downwind legs. Asymmetrics excel on coastal races with reaching legs. Many racing boats carry both and choose based on the expected wind angles. If you can only have one, an asymmetric is more versatile and more forgiving for less experienced crews.
If you're new to spinnaker sailing, start with an asymmetric. No pole to manage, one sheet to trim, and gybes are dramatically simpler. Once you're comfortable flying an asymmetric in 15–20 knots, the transition to a symmetric kite is much less intimidating.
What is the primary handling advantage of an asymmetric spinnaker over a symmetric one?
Hoisting and Setting
A clean spinnaker hoist is the foundation of a good downwind leg. A botched hoist — wraps, tangles, the sail filling before it's fully up — costs time and can be dangerous.
Pre-hoist preparation: Before the hoist, the spinnaker must be packed correctly in its bag or turtle, with the head, tack, and clew clearly identified and accessible. The halyard is attached to the head. The sheets are run outside all rigging and lifelines, through their blocks or turning points, and attached to the clews. The lazy sheet (leeward) is led around the forestay. Confirm: halyard clear, sheets clear, nothing wrapped around the forestay, headstay, or shrouds.
The hoist sequence: (1) Bear away to the hoisting angle — typically a broad reach. (2) The bowman calls 'ready to hoist.' (3) The pit or halyard person hoists fast — the sail must go up before the wind fills it unevenly. (4) As the head reaches the masthead, the trimmer sheets on and the sail fills. (5) The headsail is furled or dropped (if not already). The whole sequence should take 10–15 seconds on a well-practiced crew.
Common problems: A twist in the sail (the halyard, sheet, or guy is wrapped around the body of the sail) is visible as a constriction — the sail won't fill properly above or below the twist. The only fix for a serious twist is to drop and repack. An hourglass (the sail is twisted 180 degrees, forming a figure-8 shape) is more dramatic and must be dropped immediately — it will not resolve itself and the loads are asymmetric.
Never stand in a bight of spinnaker sheet during a hoist. If the sail fills suddenly, the sheet loads instantly — a loop of sheet around an ankle or leg can cause serious injury. Keep feet clear of all running lines during any spinnaker operation.
Why must a spinnaker be hoisted quickly?
Trimming and Gybing
Spinnaker trim is continuous — the trimmer never stops adjusting. Unlike headsail trim where you sheet on and monitor, a spinnaker requires constant input to maintain shape and prevent collapse.
The trim rule: Ease the sheet until the luff (leading edge) just begins to curl inward, then trim slightly to stop the curl. The goal is to keep the sail on the edge of a curl — maximum projected area, maximum power, minimum drag. If the luff is perfectly flat, the sail is overtrimmed. If it collapses, it was undertrimmed.
Pole position (symmetric): The pole controls the tack position. The pole should be perpendicular to the apparent wind — roughly level with the horizon and square to the wind angle. As the boat bears away, the pole goes forward. As the boat heads up, the pole goes aft. The topping lift and foreguy control the pole height — the tack and clew should be at the same height for a balanced shape.
Gybing a symmetric: The pole must be transferred from one side to the other. The sequence: (1) Ease the mainsheet for the gybe. (2) Trip the pole end from the current guy. (3) Swing the pole across and attach it to the new guy. (4) The old sheet becomes the new guy, the old guy becomes the new sheet. (5) Gybe the main. This is the most complex manoeuvre in sailboat racing — it requires timing, coordination, and practice.
Gybing an asymmetric: Far simpler. (1) Ease the old sheet. (2) The new sheet (pre-led around the forestay) is trimmed to pull the clew through the gap between the forestay and the sail. (3) Gybe the main. The sail transitions to the new side without a pole change. In light air, the crew may need to pull the clew through manually.
The spinnaker trimmer should watch the luff of the sail, not the telltales. The luff curl is the primary trim indicator. If you're constantly chasing collapses, you're trimming too aggressively — ease a few inches and let the curl develop slowly rather than waiting for a full collapse.
What is the correct trim indicator for a spinnaker?
Dousing and Common Problems
A clean spinnaker douse is as important as a clean hoist — a botched takedown at the leeward mark costs time and can be dangerous in heavy air.
The windward douse: The most common takedown. The lazy guy or retrieval line pulls the clew forward and down to the bow (or into the companionway/cockpit). As the clew comes forward, the sail depowers. The halyard is eased and the sail is gathered on the leeward side, under the main. The headsail goes up simultaneously (or before) to maintain drive through the mark rounding.
The leeward douse: The sheet is released and the sail blows forward. A crew member on the bow grabs the foot of the sail and stuffs it down the hatch or into a bag. This is faster but messier — the sail is flogging in the wind as it comes down, and it can go in the water if not gathered quickly.
The broach: The most dramatic spinnaker problem. In heavy air, the spinnaker's power rolls the boat to windward (heel increases), the helm can't counter the rounding-up force, and the boat rounds up violently into the wind — beam-on, heeled past 45 degrees, with the spinnaker flogging wildly. To recover: release the spinnaker sheet completely (the sail depowers), bear away, and regain control. Prevention: don't oversheet in gusts, ease the sheet as gusts hit, and bear away in puffs to maintain control.
The wrap: The spinnaker wraps around the forestay — caused by the sail collapsing and part of it blowing between the forestay and the mast. A minor wrap may unwrap by sailing deeper or by pulling on the sheet. A severe wrap requires someone to go to the bow with a knife as a last resort, or the halyard to be eased while the sail is unwrapped from below.
A loaded spinnaker sheet in heavy air can exert thousands of pounds of force. Never try to manually grab or hold a loaded sheet. If the sail is overpowered, release the sheet — let the sail flag. A flogging spinnaker is noisy but controllable. A loaded, overpowered spinnaker is dangerous.
What is the correct immediate response to a spinnaker broach?
Summary
Symmetric spinnakers use a pole and excel on deep downwind angles. Asymmetrics use a bowsprit and excel on reaching angles — simpler to handle with less crew.
A clean hoist requires pre-rigging (halyard, sheets outside everything) and speed — the sail must reach the masthead before the wind fills it unevenly.
Trim by watching the luff curl — ease until the luff begins to curl inward, then trim to hold it at the curl point.
Gybing a symmetric requires transferring the pole — the most complex manoeuvre in racing. Asymmetric gybes are dramatically simpler.
In a broach, release the spinnaker sheet immediately to depower, then bear away. Prevention: ease the sheet in gusts and bear away in puffs.
Key Terms
- Symmetric spinnaker
- A balanced, pole-flown downwind sail — equal on both sides, flown from a spinnaker pole projecting the tack to windward
- Asymmetric spinnaker
- A reaching sail with a fixed tack on the bowsprit — shaped like a large genoa, trimmed with a single sheet, no pole required
- Broach
- An uncontrolled rounding-up into the wind caused by excessive spinnaker power — the boat heels violently and turns beam-on
- Hourglass
- A 180-degree twist in a hoisted spinnaker creating a figure-8 shape — must be dropped and repacked
- Guy (afterguy)
- The line controlling the spinnaker pole and tack position on a symmetric spinnaker — adjusts the pole angle to match the wind
- Luff curl
- The slight inward curling of the spinnaker's leading edge that indicates the sail is at optimal trim
Spinnaker Handling Quiz
For a windward-leeward course with deep downwind legs, which spinnaker type is most effective?
What must be confirmed before calling for a spinnaker hoist?
On a symmetric spinnaker, the pole should be positioned:
What causes a spinnaker wrap around the forestay?
During an asymmetric spinnaker gybe, what happens to the sail?
References & Resources
Related Links
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North Sails — Spinnaker Trim Guide
Comprehensive guide to spinnaker trim, pole position, and handling from one of the leading sail manufacturers