Improving mainsail adjustment even with the fixed point

The mainsail sheet fixed point in recent years on cruising boats has replaced the trolley: less bulky in the cockpit, less technical, it is a solution to make life easier for cruisers.

In terms of sail efficiency, it should be emphasized that with the fixed point, much is lost. In fact, the undercarriage allows us to “change” gears to the sail and thus to the boat, increasing the angle of incidence when we carry it upwind, thus increasing horsepower, and decreasing it when we scarf downwind in fresh air. All this with the fixed point is not feasible.

Mainsail fixed point – How to improve the adjustment

How can we remedy this shortcoming? In fact, there is no substitute solution, unless we want to add bulky hoists, upwind and downwind of the boom, to try to change the angle of sail incidence with often modest results, but at this point it would have been better to buy a boat with a trolley directly. However, we can pay more attention to the sheet tension we give according to the wind conditions, and the adjustment of the vang and halyard. The only way to change the sail shape we have with the fixed point is to efficiently make the leech curvature and sail shape according to wind conditions.

Mainsail fixed point – Watch the leech curve

With the fixed point, the curvature of the leech is actually handled solely by the sheet and vang. How to adjust for this? With winds up to 10 knots, we will have to try to have the leech as curved as possible and therefore powerful. Pay attention then to how much we cock the sheet, we will need to give as little tension as possible and never more, to have a sufficiently powerful sail even without changing its angle of incidence to the wind via the undercarriage. We will cock the sheet until we see the “bubble” near the mast disappear, taking care, however, never to go beyond this tension.

Mainsails usually have wind-marking threads placed along the leech: to achieve effective adjustment the second thread from the top will need to be fully laid out, the first may “flake” but it will be better if it is laid out most of the time as well. In practice in light winds we will have to give as little sheet tension as possible, even at the cost of leaving a drop of foiled “bubble” at the mast, which will always be better than a mainsail with too thin a leech.

Working with the vang

The vang will be adjusted accordingly, up to 8 knots in fact we can just pin it slightly or leave it almost slack. As the wind increases, the vang will have to be progressively caulked, and mainsail adjustment can be developed through more generous sheet tension, at least up to 12-14 knots. At some point, let’s say around 15 knots, we will be forced to drop a bit of sheet to counteract the heeling, but the vang in a strong wind will remain quite caulked in order to thin the leech.

The halyards will follow the same pattern, but with little wind we will exaggerate a little with the adjustment taking care to keep the halyard soft until, lgo the luff, slight horizontal creases appear.

Mauro Giuffrè