Ok, we know that the ideal is to have all the telltales streaming but it is important to understand the reason for that. It has to do with the lift/drag ratio or curve. We are not going to go into the scientific aspect of those termsbecause it is beyond me anyway. It is obvious that lift is good and it is what you need to power the boat and drag is bad and must be mimimized. Incidently, lift comes from not only your sails but from the keel and also the rudder. So we know that the ideal situation we are looking for is when the wind is hitting the leading edge of the sails and both the windward and leeward telltales on the jib are streaming as are the ones on the main. There is one problem with this. When you have that scenario - both streaming - you are at the highest point of the lift/drag curve. Lift is at it highest but so is drag. So, to squeeze out more lift you should do the following. Push your adjustments a little more until you can get the windward telltale to "flip". The flip rate in medium wind is about once every 3 seconds. In winds above 15 knots, it would be once every 2 seconds. Now, if the windward telltale flips more often than that you are sailing to high and are pinching. You are sailing closer to your destination but are actually sailing slower and if you over pinch you'll really slow down. If the windward telltales NEVER flig you are sailing too low or footing. Your sailing faster but you are sailing a longer distance to your destination. Obviously, the optimum is somewhere between pinching and footing. The only way you can find that angle for your boat is to experiment and you'll see how small it actually is. The following is a balanacing act. In flat water or to cross another boat (say a large cargo vessel bearing down on you!) you should overtrim the jib slightly and get that windward telltale flipping. You want as much lift as you can get. More lift is not necessarily more power. I don't know why that is but that is what the experts who know this stuff say. If your trying to POWER through choppy seas you should ease the jib slightly and have both telltales streaming. You have to be careful here because if you foot too much (sail lower)the windward telltale will droop and you'll lose power. As you can see, a good sailor has to pay attention to his telltales and understand what they are trying to tell him. The needed adjustments can vary by a very small amount. How important is the leeward telltale? There is a fine line between a stalled sail and a luffing sail. You do not want your sail to stall and your leeward telltale is the stall indicator. If that telltale stops streaming you have to head up or sail closer to the wind. So the instant you see a reaction in the leeward telltale you should react to it. A luffing sail is easy to see but a stalled sail is not and that is why the leeward telltale is so important. The stall can be corrected by as little as a 5 to 10 dgree change of heading or angle of attack. If the windward telltale starts to really flutter all over the place it is indicating to you that you are sailing too close to the wind and are about to luff the sail, which you don't want to do unless it is your intention to tack the boat. Here's an easy tip for your jib trimmer. When the OUTSIDE telltales flips - ease the jib sheet OUT. When the INSIDE Ttelltales flip - trim the sheet IN. It is difficult to understand this stuff by just reading. You have to see it in action. So the next time your on the water devote some specific time to just reading your telltales. Adjust the controls on the main and jib and notice the reaction of your telltales. Next session will involve the 5 telltale indicator modes - full speed, acceleration, pointing, pinching and footing. I'll bet a lot of you had no idea your telltales could give you that much info.
