Positioning in the boat.
In any racing boat positioning of the weight of the crew is important. For J80 it’s crucial. General idea is that we always (except when we are gliding) need all the weight of the crew as forward as possible.
To be fast on upwind course we need some heel (tilt) in the light wind and to be on the right keel when the wind rises . So if we have some wind and the boat is heeling itself, under sail power, then all the crew should counteract this heeling by sitting on the upper, windward side. There are at least two reasons for this. First, minimizing the heeling we maximize the projection of the sails on a vertical plane and so the useful area of the sails. Then we maximize projection of the keel on the vertical plane and thus we minimize draft . And the last point is that we minimize the pressure on the rudder. But if the wind is very light, less than 5-6 kn, then sails don’t produce any heeling and we have to produce it ourself by sitting in the leeward side.
In the downwind courses sails never produce heeling. All sails power is going to the driving force which moves us. To be fast on downwind courses, if there is some wind, we need a windward heel what means that the boom and sails will be in the upper side. For this we position our weight on the leeward side. But if the wind is very light we can’t do it, because the boom will fall due to the gravitational force. In this case we heel to leeward to minimize water resistance.
Maneuvers in a light wind
Here in Barcelona light wind, up to 5-6 kn, is a very common condition. The most important rule when sailing in such conditions is to maintain speed. Why is it so important?
Imagine that you are in the race, sailing upwind 3 knots in 5 knots of True Wind Speed (TWS). As when you run, you also produce wind yourself, then wind that you will feel in the boat and which your sails really have (AWA - Apparent Wind Speed), will be around 7 knots (vector sum of the wind that you produce yourself and true wind speed). But if you will stop you will have to accelerate again in 5 knots wind. Then take in account that force that wind produces is in proportion to the square of wind speed. In other words the wind force when you are fast will be 7*7=49, and when you stop – just 5*5=25. A half! It’s always better to be fast in light wind.
The maneuver , while we usually loose our speed, is a tack. Let’s see how to tack in order not to loose and even gain more speed. This technic is named Roll Tacking.
1. Before the Roll tack crew heels the boat to leeward.
2. As the boat comes up into the wind all the crew leans out hard on the windward side, rolling the boat toward them. As the boat passes head to wind position crew sheets (trim) the jib.
3. When the sails are about to be filled with wind two-three crew members move up to the new windward side and pull the boat upright
4. Once the boat is upright all the crew moves back quickly to the normal positions.
In the same way we can accelerate a boat making jibe. The crew should move to windward right before the jibe and then, when the gennaker is filled with a wind on new tack, all the crew should fly to the new windward rail rolling a boat.