Tutorial 1, Topic 1
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Compress & Decompress

When going up the face, extend your knees, decompress and stand high. When going down, bend your knees and compress down, using gravity to gain speed.

Compress & Decompress

The art of generating speed is done by moving to precise parts of the wave while shifting your body’s weight at specific times. It isn’t just about pumping up and down in the right area on the wave. You need to know when to compress, and when to decompress your body to maximize your acceleration.

Look at advanced surfers as they start going back up towards the face. They unbend their knees, stand high, and throw their arms towards the direction they want to go to.

Once they reach the top of the wave, their board starts turning back down towards the bottom of the wave. At this moment, they bend their knees and compress their chest down towards the front knee.

If you skateboard, think of when you want to drop a quarter pipe. You need to lean your upper body down and forwards to let gravity push you down the ramp.

Pumping is a difficult technique. We teach it to students in our coaching retreats once they reach a level where they have a good stance, can angle their take off, and can trim down the line. Different things might prevent this technique to be efficient, such as the timing of the compression and extension, the upper body’s position, the stance, the positioning on the wave, etc etc. Remember it’s rare that it comes naturally and that it takes quite some practice.

The Physics behind the Technique

The extension of the body when turning up on the face of the wave works in a very similar way to skating on a ramp. Surfers are also drawing a circle as they turn, although they are going up diagonally when generating speed, compared to the skater going straight up onto the ramp.

When experienced surfers go down the bottom of a wave, they compress their knees down.

As they turn back up toward the top of the wave, they decompress by extending their body and throwing their arms towards where they want to go. As they do so, they are bringing their center of mass closer to the axis of rotation. Again, the moment of inertia is reduced and the surfer gains velocity.

An element that is commonly underestimated by intermediate students is just how much extension and throw advanced surfers actually do to accelerate.

The more the center of mass moves towards the axis of rotation, the more acceleration the surfer gets. By looking at videos of their surfing, they often realize that they could extend more and throw their arms further forward to gain more speed and make sections they once thought weren’t make-able.