The English phrase “Take off” translates as “takeoff,” “takeoff,” and is used primarily in aviation when the plane takes off from the runway.
In surfing, the same term is used to describe the moment when the board begins to slide along the wave without additional effort on the part of the surfer.
When teaching surfing, the instructor usually says something like this: “You will feel a jolt, after which the board will begin to accelerate.” The phrase “The wave pushed” or vice versa, “The wave did not push,” is also often used.
What is this magic push, after which everything changes? From the point of view of physics, this is a transition to the planning mode.
Physics is a complex science, and the deeper you dig, the harder it is. Nevertheless, it is by no means impossible to claim that humanity knows the nature of things precisely. That is why even scientists always use simplifications – they take a vacuum, spheres, generalize some interactions, some do not take into account. This article does not pretend to be published in scientific journals; some of its theses from physics are an extreme simplification. I tried to explain a very complex process on fingers and everyday analogies, which cannot be understood in a good way without integral calculation and multivolume books on hydrodynamics. But this material will help you get a general idea of the topic, but the practical advice is 100% working.
How is movement on the water
The displacement model is characterized by a sufficiently deep immersion of an object in a liquid, and for training, you need to exert a lot of effort to fight the resistance of this liquid.
The second possible option is planning, when an object moves along the surface of the water, practically not sinking into it but holding and sliding due to the high-speed pressure of the liquid and the lifting force created by it.
If the boat has a flat bottom, then when a certain minimum speed is reached, it is possible to switch from displacement mode to planning mode.
The transition from displacement mode to planning can be compared to breaking the sound barrier and is most easily explained using the example of a motorboat.
When the rate of the ship approaches the speed of wave propagation in the liquid, it turns out that the boat, as it were, is constantly trying to ride on the wave, which it creates in front of itself; this is called a wave crisis.
That is why motorboats often have bulging noses when driving. By increasing the engine power, the driver makes the boat go faster and faster, and at some point, it overtakes this wave, emerges to the surface, and begins to slide along it as if on a solid plane.
Resistance drops sharply, due to which, after entering the planning mode, you can halve the power of the motor, and the speed will not fall.
The surfboard is relatively buoyant, but it behaves differently on the wave and without it. So, for example, if you try to stand on a shortboard just in the water, without a lock, it will drown.
It is more difficult to flood a longboard or soft-top entirely if you don’t weigh 150+ kg, but the difference in stability when driving and just on flat water will be noticeable.
Thus, the surfboard allows you to move slowly in a displacement mode – when the surfer is lying on it and rowing.
Furthermore, traveling along the wave is possible only in the planning mode, so from the point of view of physics, “catching the wave” ensures the transition from one way to another.
Conditions for switching to planning mode
Modern surfboards have subtle bulges and concavities on the bottom that determine how the board will interact with the water.
But in any case, all surfboards have a bottom flat enough to move in planning mode.
The second condition is the speed required to move.
In planning mode, the Froude number ranges from 1 to 3, the exact value depends on many parameters, but it must be greater than one.
Accordingly, it would help if you gained a speed greater than the square root of the length of the flotation device multiplied by the acceleration of gravity.
For a 9’2 ” longboard it is 5.2 m / s, and for a 6’4 ” shortboard it is 4.3 m / s.
And here we go directly to the process of catching waves.
The lock pushes the panel on the wall, and the “push” falls on the tail when he is on the wall.
The wave’s energy makes the board tilt, which causes it to slide down under the influence of gravity.
The force with which the tide pushes the board at the moment of raking is proportional to the area of contact of the board with the surface of the water.
In addition, the force depends on the phase of the lock itself: the closer to the collapse, the more energy the wave crest carries forward; that is, the wave pushes better.
Thus, the speed of a surfer when he rakes is the sum of the rate that he developed with the help of rowing and the speed that the wave gave him.
The board will switch to planning mode; the surfer will catch the wave. On the other hand, if the rate is not enough, the surfer will not “rake,” the lock will travel further, leaving him behind.
How to increase your chances of taking teikof
In addition to directly contributing to the final speed, it does this: the wave pushes the board as long as the surfer is in an inclined position on its wall.
This time, in turn, depends on the difference between the speeds of the wave and the surfer.
The area that the wave pushes depends more on the width of the board than on the length since the wall of the wave is curved, and when raking, not all of the board is in contact with the surface.
In addition, the wave’s energy is distributed so that the point of application of the force is narrow – conventionally, the wave pushes the tail of the surfboard.
That is why it is easier to get rid of a short but very wide bun than, for example, on a long but narrow gana.
In the shallow section on the shoulder, the wave gives the board a slight acceleration.
The size of the board partially offsets this; that is, the equipment affects the width of the section in which it is possible to catch the wave.
At the same time, in the right place of the critical area, it is possible to do “No paddle takeoff,” that is, start without a single stroke.
The initial speed is zero, but by setting the correct forward impulse and synchronizing it with the moment when the wave pushes the board, you can accelerate sharply and instantly switch to the planning mode.
Knowledge of hydrodynamics provides a life hack for raking. The fact is that when switching from displacement mode to planning, the position of the board (or boat) relative to the water changes.
The bow drops, and the stern emerges from the wave. If the speed for the transition is a little bit lacking, the same effect can be achieved by redistributing the weight, and the consequence will be the reason – planning will begin.
On a longboard, you can still bend your legs, but this must be done technically so as not to swing the board, so this can hinder beginners on the contrary.
Thus, a successful start depends on a range of factors that cannot be calculated deliberately.
But on the other hand, the brain perfectly accumulates data, quickly performs calculations, and gives a ready-made answer – “row, take” or “skip, don’t rake.”
It is called experience, and it is accumulated by trial and error. You probably already knew that to catch a wave, you need to choose equipment by your experience, learn to row technically, and choose the right place to start.
Now you still know exactly how it works. And the secret to success is practice, so surf. But surf smart!