Kitesurfing, a hybrid of kiting, windsurfing and wakeboarding, allows you to harness the power of both the wind and the ocean to travel at record speeds and jump to astonishing heights in the air. Kitesurfers glide across the top of the waves on a board that's similar in size and shape to a wakeboard while holding onto a kitesurfing kite. The basic objective of kitesurfing is to do tricks and to see how high and long you can jump off waves.
Although kitesurfing might seem like the latest extreme sport fad, we can actually trace its roots to 13th century China. Rather than an activity for adventurous water sport enthusiasts, kitesailing, as kitesurfing was originally termed, served as a mode of transportation. The 13th century Chinese used sails to harness the wind and increase the speed and stability of their canoes as they glided across the water.
Physics of Kitesurfing
To understand the physics of kitesurfing, you first have to understand how a kite works and some basic principles of aerodynamics. A kite flies, in accordance with Newton's laws of motion, as a result of the forces being applied to it. Since a kite is heavier than air, it needs the motion of the wind to generate the aerodynamic forces of lift and drag. The movement of the air flowing past the kite creates drag, while the lift is the movement perpendicular to the wind. The interaction of these forces determines how well the kite will fly. The ratio of lift to drag and the stability of the kite are tied to the length of the line; that is, the more line is released, the more drag is created.
To launch a kite, you need to create a lift force that is greater than the weight of the kite. The lifting force of a kite is created by the deflection of air downward; the change in the kite's momentum produces an upward force because the air traveling over the top of the kite is going faster than the air that's passing underneath. This fast-moving air produces less pressure, and because there's less pressure beneath the kite, it's forced upward.
The velocity of the air blowing at the kite is the most important factor in determining the size of the lift. If you face the kite with the wind at your back, the wind provides relative velocity to lift the kite. Standing still, a kite will usually fly without much additional motion on your part because wind velocity increases with altitude. In general, a wind speed of 10 to 18 knots is ideal for practicing kitesurfing.
Once a kite is launched, it will remain at an altitude in which all of the forces are balanced. If you pull on the kite's line, you can increase the velocity of the kite and thus increase its lift. This is how movement is achieved in kitesurfing. By using your weight to pull the kite, you increase the speed at which the kite moves.
In order to increase or decrease your speed while kitesurfing, you have to change the position of the kite. When the kite is overhead, it's in the neutral position and not providing any pulling force. When the kite is toward the water in front of the body, an area called the power zone, the wind blowing horizontally catches the kite, and pulling force is created. When the kite is in the power zone, three degrees of power can be achieved. For minimum power, lower your kite and hold it in a constant position. For medium power, steer deeper toward the horizon and turn back and upward repeatedly. For maximum power, steer even deeper.
Launching, Jumps and Kitesurfing Tricks
First things first, you have to launch your kite. You shouldn't try to launch near people, and beginners should launch from the beach before heading out to the ocean. After you've got all of your gear together, you should make sure your kite's lines are flat and stretched out. If you're using an inflatable kite, you should begin inflating a few minutes before you intend to launch. Next, head to the edge of the water. Once you're about a foot into the ocean, have a spotter hold your kite handle and strap your feet onto your board.
Once you're in the water, you have to know how to control your kite. You should start on your back in the water with your board in front of you and the kite floating in the air above you. As your kite gains power, you'll be pulled forward out of the water. Pull the kite into the maximum power zone to gain some momentum and push off into the water. In order to turn your board, put the kite in the neutral position and use your control bar to turn the kite in the opposite direction.
After you've mastered these basics of kitesurfing, it's time to try some tricks and jumps. In order to jump, you first dive the kite down to make your board move quickly. Then, in a very quick motion, move the kite upward and backward to about an 85-degree vertical angle. Next, bend your knees and edge over quickly on your board's rail (the edge of your board). When the kite begins pulling you, release the rail and jump. While you're airborne, place your feet back on the board in front of you and then move the kite forward so that you'll maintain momentum when you land.
Most kitesurfing tricks are borrowed from skateboarding and wakeboarding. Here are a few of the most popular kitesurfing tricks:
- Grab: Grabs are the basis for board-off tricks. In order to perform a grab, start your jump like normal, and when you're airborne, take your back hand off your control bar. Then, bring the board close to your body and grab it with your back hand. You then release the board and land.
- Spin: Depending on how long you're jumping and how fast you're spinning, you can spin once, twice or even more times. To spin, begin your jump, and once you're in the air, turn your head and shoulder in the direction you want to spin. Once you've completed your spin, turn your head and shoulders in the opposite direction and extend your legs for a landing.
- Invert: To invert, you turn yourself upside down while airborne. To execute an invert, bring your feet up in the air as soon as you're airborne. When you're finished, bring your feet down and land as usual.
- Board-off: As its name implies, in a board-off, you'll take one or both feet off of your board. To perform a board-off, grab your board as soon as you're airborne and take one or both feet off of your board. Then, put your feet back in the straps and extend your legs for landing.