Squaring the pole means trimming the afterguy to pull the spinnaker pole aft, away from the headstay and toward the shroud, as the boat bears away onto a deeper course. The opposite action, easing the guy so the pole swings forward, is called easing or letting the pole forward. A beginner learns squaring as the thing the guy trimmer does when the helm turns downwind; an experienced crew understands it as the primary control for a symmetrical spinnaker, because the pole angle sets where the luff of the sail sits relative to the wind and therefore how much of the sail is actually working.
Why the pole angle matters
A symmetrical spinnaker only projects its full area when its luff is held out to windward of the boat. The pole is the device that does this, and the guy is the line that positions it. The working rule is that the pole should be roughly perpendicular to the apparent wind. On a broad reach with the apparent wind on the quarter the pole is well forward, almost touching the headstay. As the boat bears away toward a run and the apparent wind moves aft, the pole is squared back until, on a dead run, it lies against the shroud and the spinnaker is spread right across the bow. Every few degrees of course change wants a corresponding adjustment of the guy.
Get this wrong in either direction and the sail suffers. Pole too far forward for the wind angle and the spinnaker rotates to leeward behind the mainsail, collapses in the main’s wind shadow, and the boat rolls. Pole squared too far and the luff is dragged to windward, the sail becomes flat and starved, and the leech hooks in toward the main. The tell-tale of a correctly squared pole is a spinnaker whose luff curls evenly when the sheet is eased and whose two clews sit level.
Coordinating guy and sheet
Squaring the pole is never done in isolation. When the guy comes aft the sheet must be eased by roughly the same amount, otherwise the sail is simply dragged around the boat and oversheeted. The trimmer calls the changes: “squaring two” for the guy trimmer, “easing two” for the sheet. On a well-drilled boat the helm, sheet trimmer and guy trimmer work as one unit, with the guy following the helm’s course changes and the sheet following the luff.
- Helm bears away a few degrees, calling the change.
- Guy trimmer squares the pole so it stays perpendicular to the new apparent wind.
- Sheet trimmer eases until the luff curls, then trims a touch.
- Pole height is checked: both clews should fly at the same height, with the tack lifted or lowered on the topping lift and downhaul to make the luff break evenly.
Practical technique
Guy loads are heavy, especially on larger boats, so the guy should always be on a winch with a good lead. Square the pole in small steps rather than one big heave, and watch the sail as you do it. In gusts, squaring the pole a little further is a useful way to open the slot and depower a spinnaker without rounding up. In lulls, let it forward so the sail rotates to leeward and fills more easily. Downwind in waves, a slightly forward pole helps the sail keep drawing as the boat slows on the back of a wave.
Cruising versus racing
Racers square the pole constantly, chasing every shift and every wave, and they set up dedicated guys with tweakers and twing lines so the pole position can be changed instantly. A cruising crew flying a symmetrical spinnaker will set the pole for the average course and adjust every few minutes, which is perfectly adequate for passage-making. UK Sailmakers advises cruisers using a symmetrical kite to mark the guy at the positions for a reach, a broad reach and a run so that the crew on watch has a reference; those with an asymmetric spinnaker do not square a pole at all, which is one reason the asymmetric has become the cruising sail of choice.
Related terms
The afterguy or guy is the line that controls the pole; the foreguy or downhaul stops the pole from skying, and the topping lift supports it. A pole squared fully aft is said to be on the shroud; a pole eased fully forward is on the headstay.
Frequently Asked Questions about Squaring the Pole
How far should I square the pole on a dead run?
Almost all the way, so the pole lies just off the shroud and the spinnaker is spread across the bow. Leave a small gap so the pole does not chafe the shroud or load the pole end.
Why does the spinnaker collapse when I square the pole?
Squaring the pole without easing the sheet oversheets the sail, and squaring too far for the wind angle starves the luff. Ease the sheet as the pole comes aft, and check that the pole is still perpendicular to the apparent wind.
Squaring the pole is the small, repetitive adjustment that keeps a symmetrical spinnaker doing its job. Keep the pole square to the apparent wind, keep the clews level, and keep the sheet moving with it, and the kite will pull the boat downwind as it was designed to.