You are racing down a run in 5 to 10 knots of wind flying an asymmetrical spinnaker. There is a boat several lengths behind you that is threatening to give you bad air. You know it's very important to keep your air clear in these conditions. What is the best way to know if your wind is being affected by the other boat?
Correct Answer: Look up at the wind pennant at the top of your mast
Explanation : The best way to keep your air clear is by watching the wind pennant at the top of your mast. This points in the direction of your apparent wind and shows where your sailing wind is coming from. If your wind pennant is pointing at the other boat, you have a problem! The wind pennant on the other boat can also be helpful. It may not be quite as reliable as the pennant on your mast, but it will show you the direction that their wind shadow extends. The ripples on the water are not a good reference because they show the true wind direction, which is often quite different from your apparent wind (the direction from which your sailing wind comes). Your instruments are also unreliable because they aren't sensitive enough to pick up the subtle changes in pressure that occur in wind shadows.