downhaul for light winds... Should the wind drop, or should your sail be small for the wind strength, less downhaul tension will firm up the leech and make the sail body fuller.  This reduced trim generates greater low end power. Note that as soon as the winds are sufficient for easy planing, it is a good moment to experiment with more downhaul tension.  The fresh feeling of free speed will set your windsurfing soul free. The downhaul adjustment range between ideal low wind trim and ideal high wind trim may be as much as 4cm. Masts influence rig performance. It is best to use the recommended mast for the sail. If a softer/shorter mast is used, the rig becomes more flexible. The handling becomes easier in high winds, and the rig is easier to close down on the board ("closing the gap") in strong winds. A stiffer mast will have the opposite effect; the rig will become more difficult to close in the upper wind range, will go upwind more efficiently and become more light wind oriented.