Setting your sails to the Boat by Michael McNamara



FORESAIL When the wind is flowing over the sail properly the windward windtufts will angle upwards and the leeward windtufts will be horizontal. 

In order to point as high as possible, the sail must work as a complete unit throughout its length. So, make sure that all three windward windtufts collapse at the same time when you luft up. If the top windtuft collapses first, the leech is too slack and so, the fairlead must be moved slightly forward and/or the sheet tensioned. If the bottom windtuft goes first, then slacken the leech by easing the fairlead aft, and/or easing the sheet. 

Keep down to a minimum the amount of jib luff sag (which gives unwanted fullness at the front) by adjusting rig tension so that the leeward shroud does not go slack. 

If there is an eye at the tack, the luff of the sail can be tensioned to suit the weather conditions. This usually means tightening the luff in a breeze or when the sail gets older. If horizontal creases appear along the luff then tension it slightly until they disappear but do not over tension as this drags the flow forward and ruins pointing. 

MAINSAIL The sail is designed to give optimum performance when the last 6″ of the top batten and the last 2′ 0″ of the boom are parallel Use kicking strap and mainsheet to achieve this i.e. if the top batten is more open than the boom tension both, while if it is tighter, ease them both. 

Set the luff tension of the sail so that when running in light winds the sail is smooth without ndgmg. If a vertical ridge occurs ease the luff tension until it disappears. If this is hard to remove then check that the mast is not bending backwards in the middle and forward at the top this will prove disastrous on the run. Angle the spreaders aft and/or let the mast move forward at the mast gate until it is straight or bent forwards slightly in the middle (prebend).