Mainsail adjustment that can make a difference to boat speed

mainsail trimmingThe adjustment of the mainsail carriage, which seems unfashionable on modern super cruising boats, is still a crucial aspect when we talk about the main “engine” of the boat, the mainsail precisely. The basic theory states: upwind with lots of wind trolley the trolley goes downwind, with little wind trolley upwind. In principle this is so, but it is with the finesses of this adjustment that we can make a difference on the upwind speed of our boat, in racing but also in cruising, for example in light winds.


With little wind, upwind, it is necessary to gradually bring the carriage upwind from the center of the boat, even almost to its upwind apex. Doing so changes the angle of incidence between the wind direction and the sail, closing it, and increasing the load on the mainsail, thus indirectly on the rudder, resulting in a more gyratory boat and more bite on the appendage.

The risk of this operation, however, is to end up with the leech excessively closed and oriented too far upwind of the boat center. Therefore, when we bring the carriage upwind, it is necessary at the same time to leave a little bit of sheet, so as to slightly warp the top of the sail and make the profile efficient.


If we do the two operations in the right measure we will notice that the boat will take a slight gyre tendency even if there is little wind. Conversely, if we pull the trolley upwind without leaving a bit of sheet, it is easy for the mainsail to stall and the boat to begin to lose speed, actually increasing the drift. If we are in a situation of 8-10 knots of wind, with a few gusts above that, the mainsailer will have to be quick to dump a few inches of gear at the entrance of the stronger pressure, lest the boat swerve and heel a bit too much forcing a major rudder correction that would brake the boat. You scarf down a few inches downwind, close a bit of sheet, and go back to do the reverse operation at the end of the gust, that is, still on carriage and open sheet again. And so on, following the sequence of bursts and dips.


The more the wind intensity increases, the shorter the cart movements, if we are not experienced and trained randers, will become. Most sport boats that are equipped with undercarriages above 12 knots of wind have a good load on the rudder and a fair amount of gyre tendency, so it will not be useful, or even counterproductive, to keep the undercarriage far upwind. Up to 15 knots it will be enough to keep it just above the centerline, above 15 it will start to go downwind of it. From 12 knots and up we will keep the undercarriage much steadier than in light winds, and we will start working more with the sheet. In stronger winds if a strong gust comes in we will be more effective by dropping the sheet and holding the gear in its position, just above or below the centerline depending on the intensity. We will help ourselves to control the leech with the vang, which if with little wind is just pinned, as the air rises it should be gradually capped.

Mauro Giuffrè


The journalists of the Sailing Newspaper, strive every day to ensure quality, up-to-date and correct information about the boating world free of charge through their websites. If you appreciate our work, support us by subscribing to the magazine. The annual subscription costs only 49 euros and we give you a nice gift


Daily interviews, boat trials, webinars. The whole sail, minute by minute. But on video! CLICK HERE To sign up, it’s free!


To stay up-to-date on all the news from the world of sailing, selected by our editorial staff, sign up for the Sailing Newspaper newsletter! It’s super easy, just enter your email below, agree to the Privacy Policy and click the “Sign Me Up” button. You will then receive on your email, twice a week, the best sailing news! It’s a free service and you can unsubscribe at any time, with no obligation!

Once you click on the button below check your mailbox





Leave a Comment

Your email address will not be published.

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Read the latest issue

Are you already a subscriber?

Latest announcements
Our socials

You may also be interested

processo alla scuola vela

Sailing school trial. Your (reasoned) comments

How to make the number of sailors at zonal and local regattas in Italy grow again? How to avoid youth dispersion after the Optimist years? And how to manage to win more than one medal in three editions of the

L'equipaggio di White Hawk, vincitore della prima J/70 Corinthian World Cup a Riva del Garda

J/70, the strongest non-professional team is Italian

Gianfranco Noah’s White Hawk wins the first J/70 Corinthian World Cup in history. The event, which was held June 1-4 in Riva del Garda, included. 4 days of racing for Corinthian-only crews, but, due to very unusual wind conditions for

Scroll to Top
Iscriviti alla nostra Newsletter

Ti facciamo un regalo

La vela, le sue storie, tutte le barche, gli accessori. Iscriviti ora alla nostra newsletter gratuita e ricevi ogni settimana le migliori news selezionate dalla redazione del Giornale della Vela. E in più ti regaliamo un mese di GdV in digitale su PC, Tablet, Smartphone. Inserisci la tua mail qui sotto, accetta la Privacy Policy e clicca sul bottone “iscrivimi”. Riceverai un codice per attivare gratuitamente il tuo mese di GdV!

Una volta cliccato sul tasto qui sotto controlla la tua casella mail