The purpose of this tuning-guide is to give our clients in the Finn class some guidelines on how to get the most out of their North Sails.
Follow the guidelines, but always experiment and try finding your own trim. The weight of the crew, the balance of the boat, the stiffness of the mast together with specific local wind and sea conditions all have influence on the fastest and final trim.

Upwind Trim

When sailing upwind in the Finn it is important to remember that you are paid to hike. If your sails are trimmed perfectly and you are just sitting on the side enjoying the scenery, you will be slow. The Finn is a big heavy boat with lots of sail area and you must use every once of your body weight to keep it moving fast through the water. Weather you droop-leg or straight-leg hike make sure that you are confortable (if that is possible!) and strong and remember that you can always hike harder.

In less than 5 knots, when hiking is not required, concentration and setup are crucial. We find that raking back an inch or two gives the boat more feel and brings the boom closer to parallel. The best way to make this adjustments is to move the mast back one position at the deck and keep the mast step in the same place. In light air the outhaul should be 3" forward of the black band and the inhaul 3" back from the aft edge of the mast. The traveler should be adjusted so that the end of the boom is 6" inboard of the gunnel. Play the mainsheet so that the top telltale stalls 20% of the time.

In near drifter conditions, it is next to impossible to get the top telltales to fly and boomvang is required to flatten out the leech. When doing this pull the outhaul to the black band and bring the traveler near centerline. Put enough vang on so that the top of the sail is flat and the telltales start to fly. You may find that tacking with this much vang on is difficult so you may have to ease it when you tack. It is important to mention that these are only conditions where you will ever put on any boomvang upwind. Boom height and position is all controlled by mainsheet and traveler settings, putting boom vang on upwind in any thing except the lightest of conditions will endanger your life.

As wind velocity increases, your primary concern is leech tension and traveler position. As you slowly tighten your leech by pulling the mainsheet the traveler should be let out until the boom hits the deck and the end of the boom is 2" in from the gunnel (12 knots). The inhaul is tightened before the outhaul and should max out at 12 knots.

In over 6 knots, move your rake back to the standard position of 22'3" and 22'4" over 12 knots. This will give you the proper leech tension when the boom is on the deck. If you are a lighter sailor err on the raked back side and if you want to foot more also err on the raked back side. 

Downwind Sailing

Try to adjust all sail controls before you reach the weather mark so that you can concentrate on surfing that first wave instead of messing with your lines. Release the cunningham, let the inhaul of 6", ease the outhaul 2" and preset the vang. The vang should be set so that the top batten is 2-3┬░ open relative to the boom. Pull the board up as high as you dare when going down wind until the board is flush with the bottom of the hull.

Play the mainsheet directly from the boom (1:1) until it fells like you are going to be pulled out the boat and are not longer effective. At this point switch to 2:1 (sheet deadended at the main ratchet block then through the boom and to your hand), as it more manageable and safer. The Finn likes to be sailed with a little weather heel and low angles, but not to the lee. 

Good luck on the water!

Tuning Guides - Finn On the Water

Wind (knots)

(Boom above deck)

(End of boom
to gunnel)

(Tack to mast)

(Clew to
black board)

Rake Measurement

18"-12" up

6" in




12"-3" up

6" in





3" in to 0





On deck

3" outside





1"-2" up

6" outside




Contact the Finn Experts:

Paul Hobson

+44(1329) 443430 Work