The wind window by Kitesurf College

Transcript

1. ›

   Introduction

   0:00

   The wind window is a fundamental concept in kitesurfing. Understanding it will help you a lot as you begin your lessons.

2. ›

   Wind window basics

   0:21

   The window is the space in which your kite can fly. It's located on your downwind side, never upwind. It's shaped like a half dome, whose radius is the distance between the pilot and the kite, roughly the length of the lines. The kite's position in the window is described with clock numbers: 9 o'clock means the kite is to your left, near ground level; then 10 and 11 o'clock on the left side; 12 o'clock is the center of the window; on the right, 1 and 2 o'clock, then 3 o'clock at ground level. 10:30 and 1:30 are often called simply 45 degrees. The window has different power zones. With your back to the wind, the area in front of you, directly downwind, is the high power zone, in red: the kite moves very fast there and produces the greatest force. Moving away from it, up or across the window, you reach medium power, in orange, then the low power zone, above your head and to your sides. The edge of the window is the furthest upwind the kite can fly; around it is the no power zone, where the kite can't support its own weight.

3. Wind window diagram2:57
4. ›

   Steering and kite position

   3:03

   In the power zones, the leading edge flies forward very fast; the kite slows down as it reaches low power. Generally, steering with gentle movements keeps the kite in low power: the leading edge always points toward that zone. Turning more sharply aims it deeper into the window: that shows why firmer steering makes the kite pull harder. These moves are called power dives, here to the left of the window, then to the right, from weak to stronger dives. These demonstrations were filmed on land with a relatively large kite, purely so you can see what's happening: when learning, you start with a tiny trainer kite, with an instructor by your side so no one gets hurt.

5. ›

   Ground level window

   5:40

   As well as the full wind window, here's the ground level window: the power zones for a kite at ground level. High power is directly downwind; moving away from it, medium power, then low, and eventually no power at all. It's a useful concept when learning to launch your kite.

6. ›

   Wind effects

   6:21

   This may sound obvious, but when the wind direction changes, so does the window. In clean wind, the power zones are very predictable, but they can change: low obstacles, mangroves, sand dunes or even waves, create drag, and the wind is weaker near the ground. In stronger wind, the power zones expand and the kite sits comfortably on the edge of the window; in light wind, they retract and the kite needs to sit deeper in the window to support its weight. Gusty wind keeps changing the zones, which causes numerous problems.

7. ›

   Power zones simplified explanation

   7:29

   To get a feeling for why the power zones are where they are, let's look at the window from crosswind. A kite positioned downwind, in high power, cuts across the path of the wind, whereas a kite near the edge of the window lines up with the wind and has less interaction with the airflow. The other reason is speed: downwind of you, the kite flies much faster, and the faster it flies, the more the airflow across it increases, and the pull with it.