In Part 4 of our 12-part series professional sailing coach Pip Hare considers how to trim your sails for optimum performance – and comfort – upwind

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Sailing to windward on a badly trimmed boat seems like punishment. We have all felt that jarring crash when the boat falls off a wave, or wondered whether we might be better off under engine when the GPS’s ETA refuses to fall.

The intricacies of good sail and boat trim fill many books, so this article will instead focus on just a few areas that will improve your boat’s performance, thereby reducing your passage times and putting some fun back into sailing upwind in moderate to heavy airs; light airs sailing will be covered later in the series.

See our video of SAIL FASTER SAIL SAFER Part 4 where Brian Thompson gives his tips for sailing to windward.

The great circle

Sailing well to windward is all about equilibrium; the relationship between the helm, the trim of the sails and the boat’s angle of heel must be carefully balanced to ensure best performance.

Every adjustment made to the trim in one area of the boat will have an effect elsewhere. As a starting point, set up the jib, then the main and monitor the angle of heel and the feel of the helm. With every change note your boat speed and apparent wind angle and keep tweaking until you have the perfect balance.

Jib trim


The jib halyard controls the position of the draught of the sail – aim to keep this just over a third of the way back from the luff. As the wind increases, you will need to use more halyard to keep the draught in this position. Newer or laminate sails generally need less halyard tension than older Dacron and roller-furling sails.

Sheet and jib cars

To get the best performance from your sail you need to use the jib cars in conjunction with the sheet. They control the sail’s leech profile, so tensioning the jib sheet with the cars forward will pull the clew down and close the leech at the top of the sail. Moving the cars back allows the clew to rise up and the top of the sail to twist and open.

Luff telltales are a good indicator of the best position for the car; aim to have top, middle and bottom telltales breaking at the same time. A higher inside telltale breaking before the others indicates that the car needs to move forward and vice versa.

Be careful not to move the car too far forward as this will close the top of the sail too much and direct the airflow into the back of the main, causing excess backwinding – always check the effect your jib trim is having on the main.

In stronger winds, moving the cars aft will allow the top of the jib to open, so help to reduce heeling moment.

With roller-furling headsails the jib cars must move forward as the sail is reefed. It is a good idea to have a spare sheet handy to change between forward and aft tracks.

Trimming the jib:


Jib cars with adjusters:

3 jib car on track


Mainsail trim


Aim to position the draught around the mid-point of the sail. The main halyard and cunningham can be used to achieve this, using the same principle as for the jib.

The extra purchase on a cunningham should allow you to adjust luff tension without easing the sheet.


When the boom is close to the centreline, the mainsheet is the primary control of the leech profile of the mainsail; increasing the mainsheet tension has a similar effect to moving the jib car forward as it closes the top of the sail. A closed sail will generally allow you to point higher, while sacrificing speed, with an open sail the reverse is true.

Telltales on the leech of the main can help trim. A flying telltale indicates airflow over the leech of the main, a hanging one indicates a stalled sail. Aim to have the top telltale flying around 70 per cent of the time.

Bringing in the mainsheet will make the airflow stall more, giving better pointing, but less speed. Easing the mainsheet has the opposite effect. If you don’t have leech telltales, matching the main leech profile to that of the jib is a good start.


The traveller is often overlooked, but used correctly it can make big improvements to your upwind progress. When beating, the traveller controls the angle of the mainsail relative to the wind and by pulling the traveller to windward you can get your boom on (or close to) the centreline, thereby maximising the power in the sail.

The further forward your mainsheet along the boom, the more traveller you need to get the boom close to the centreline, especially if the sheet is over the coachroof.


Gusts or increasing breeze creates heel, so you can depower the main in two ways. It is worth experimenting to find out which method maintains the best balance and speed on your boat in different conditions.

The first method is to keep the main sheeted on while easing the traveller down to reduce power. This method is often preferred in flat-water gusty conditions.

The second is to keep the traveller locked off, but ease the mainsheet, which allows the wind to spill from the top of the sail, effectively reducing heel. You can compensate for this by pulling the traveller to windward, which helps to keep the boom on the centreline and maintain drive from the bottom of the sail. This method is often preferred in waves as the twisted main copes better with the large wind changes created at the top of the mast when pitching.


As the wind increases, pull on the backstay, this will reduce forestay sag, giving better pointing from the jib and will flatten, so depower the mainsail.

Backstay tension:


Angle of heel

Experiment with your sail trim, watching the boat speed to find your optimum angle of heel; it will often be less than you expect. Trimming the sails to maintain this angle will stop the helmsman from having to make excessive helm movements.

In gusts the helmsman can feather the boat into the wind to reduce the angle of heel, but a long-term solution must be found by depowering the sails.

Be at one with your boat

Take time to enjoy steering upwind and learn how your boat feels when it is going well. The feel of the helm should tell you a lot about your sail trim – if it is hard to steer, then trim the sails again. Most boats sail best with just a little weather helm upwind.

And don’t forget to watch your apparent wind angle as well as your speed. It is all too easy to sail fast without pointing, meaning that your VMG does not improve, you just sail further!

Top tips

  • Practise steering upwind with your eyes closed – this will help you feel the angle of heel and get an impression of how well the boat is balanced.
  • Inclinometers down below and on deck will help you check the angle of heel when the autopilot is driving.
  • Mark and measure your jib car and traveller positions and when the boat is set up well record the wind speed, sea state and car positions to enable you to reproduce the sail-set easily in future.
  • Don’t forget to ease the tension on a roller-furling headsail halyard at the end of a day’s sailing.


Screen shot 2011-12-07 at 16.16.59Single-handed ocean sailor Pip Hare has clocked up thousands of miles racing and cruising. Among her achievements are five solo transatlantics, including the OSTAR and two Mini Transat races. She also works full-time for the RNLI on sea safety and is Consulting Editor on Yachting World. See also her series on short-handed sailing

Photo: Thierry Martinez

Photo: Thierry Martinez


Brian Thompson is a vastly experienced sailor, who has raced solo and fully crewed round the world in monohulls and multihulls. His most recent record-breaking run was with Loïck Peyon aboard the trimaran Banque Populaire V, which sailed round the world in a breathtaking 43 days

SAIL FASTER SAIL SAFER Part 5: Solo sailor Brian Thompson, holder of 26 sailing world records, explains how he helms to get the most from a boat in different sea conditions


12 part series in association with Pantaenius