From the first time he succeeded in "following the blue of the wave", to the most beautiful trajectories of his life, the Still-point concept symbolizes the surfer's quest. For the beginner it is just the place to aim to achieve the best trajectory possible. For other surfers, whose experience mirrors a life of Waterman, it's just...exactly the same.
The Still-point is an expression that describes both a place, a moment and an experience. It focuses the spatial, temporal and emotional dimensions, in a bubble guiding the surfer. Refuge and resource, memory and rendezvous, the Still-point lives in every surfer, in a unique and yet universal way. The translation "bubble of silence" reflects well this escape from daily thought. The emotion linked to the Still-point often leads this concept, however brilliant, towards obscure metaphors with regard to classical physics.
We will therefore try to shed light on it with a rational definition, nevertheless reflecting the subjective experience of the surfer. We will thus help the scientific spirit observing the scene from the edge of the beach, to establish contact with the explorers of the metaphysics of surfing. From studies and achievements with various shapers, it emerges the importance of extracting from the testimony of surfers, the precise data allowing to design the best possible board. The fact is, in the expression of his passion, the surfer often uses a terminology undermined by very subjective interpretations. These freedoms of language unfortunately blur the transmission of precious experiences.
On the other hand, the shaper sometimes unintentionally uses arguments with theoretical ambiguities. The hydrodynamics of surfing is a complex science because the factors are multiple, but it is a powerful theoretical tool, offering an undeniable margin of progress for the shaper as for the surfer. It is therefore essential to use rational definitions so as not to create more complexity in its study. A mystical description of the Still-point marvelously feeds an end of the evening between friends, but it does not provide a method for tracing the outline, when one concretely establishes, the geometry of a board in the Shape room. We will therefore see in detail how surfing professionals will benefit from seizing a common and pragmatic definition of the concept of Still-point, as a zone of evolution generating maximum acceleration.
May the intuition of my interstellar surfer friend be reassured, defining the Still-point does not deprive it of its emotional dimension, which escapes the tyranny of reasoning. On the contrary, it is an opportunity to travel again on this path between reason and instinct. It is possible that surfing reveals an intuitive vision of physics, offering us an animal and effective reading of our environment. To reason in harmony with our instinct, let's start by reasonably defining the Still-point universe.
POSITION OF THE STILL-POINT: IF IT EXISTS, IT MUST BE SOMEWHERE...
The Still-point can be considered as the place offering the optimal energy potential: Let's assume that the Still-point is the area where the surfer can exploit the power of the wave with the best possible efficiency. Efficiency here being a positive concept reflecting the share of natural energy that we manage to transform into a trajectory. Let's imagine that the surfer has succeeded in his take-off (take-off in the wave), he completes his bottom turn (bottom turn) and now travels the wave laterally, slightly ahead of the breaking. The speed of the swell wave is acquired by it. The speed of the surfer relative to the swell displacement is therefore zero. The sources of energy supplying the surfer are, at this point, the force of gravity and the speed of the flow rising from the base towards the crest of the wave. The additional energy of variation in height and that emanating from the maneuvers produced by the surfer are considered here as zero. The maximum energy potentially exploitable by the surfer is then focused in the area where the verticality is the most perfect.
The verticality makes it possible to apply to the rising flow, the maximum of the force of gravity, via the weight of the surfer. In reality the surfer never manages to maintain himself in this verticality, but it remains the zone that is theoretically the most fertile in energy. This vertical zone of the wave is also the zone where the rising flow has a speed equal to the swell speed, which, added to the trajectory speed, generates a significant and well-oriented relative flow, allowing low planing angles and therefore low drag. This flow relative to the Still-point also allows rail and fin drive effects that the shaper tries to capture. We will see this aspect in detail and we will come back to the importance of being able to surf “high” in the wave.
Let us add that the Still-point is close to the surface level of the ocean at rest, so it has a double meaning: it is also the still water level. The Still-point thus reflects the Energy and the absence of Energy in the same place. The duality of this vision contributes to freeing the perception of the surfer from the embrace of time.
There are often in a wave, simultaneously, several positions meeting the criterion of verticality, we can estimate that the Still-point is on the line connecting the vertical zones of the wave:
The subjective vision of the line of possible Still-points (Gray band passing through St1 and St2) according to the various positions of the surfer (centers of gravity G1, G2, G3) can be schematized as follows:
Schematic subjective view of the Still-point area. The gray band represents the vertical areas of the wave. The sources of acceleration are in this zone. For the surfer in G1 this band is above his center of gravity, he cannot extract the maximum energy. He will have to expend energy to reach this area. If he has a surplus of speed compared to the displacement of the Still-point, he will be able to give up a little kinetic energy to go up to join him, otherwise it is better to get out of the wave. The surfer in G2 is on the lower part of the acceleration strip, his room for maneuver is low, but he can exploit the power of the upflow at the Still-point to accelerate. The surfer in G3 has more leeway, he surfs the top of the wave, he glides in the rising flow by recovering the maximum of energy, he can modify his angle of attack to increase his horizontal speed.
So here we are with a geometric and dynamic definition of the Still-point respecting the experience of the surfer, usable for the hydrodynamic analysis of a board evolving in this zone.
TRANSFORMING TIME INTO SPATIAL ALIGNMENT :
By visualizing a line passing through the positions of the Still-point along the wave, the various moments T1, T2, T3… are replaced by a guideline. This direction forms an angle with the horizontal, similar to the attitude in aeronautics, which you just have to aim for to adjust the incidence with the flow.
The surfer's spatial vision, when he uses the Still-point trajectory line as a reference, is a slide rule where he places his center of gravity, using the angle formed by his gaze and the horizontal given by his ear internal.
Speed is conventionally formulated by a duration and a distance (m/sec), the notion of speed is therefore linked to time. In his subjective vision the observer no longer evaluates the speed, nor the time it will take to reach a point. The surfer places himself in the zone that produces the acceleration, if this zone accelerates, he accelerates with it without reflection or action on his part. By freeing itself from the notion of speed, the mind thus manages to evolve beyond what it could envisage in a temporal reference, it follows the geometric logic of the wave in a "timeless" reference. Hydro-dynamically speaking, the board planes in the rising flow, the surfer adjusts the angle of incidence (the trim) to keep his center of gravity in line with the trajectory of the Still-point. A directional look in the axis connecting ST1 to ST2 (fig. above) and a board responding intuitively to his intentions plunge the surfer into a feeling of calm. This "geometric" thinking is similar to inner silence, a state of reflex, the surfer knows where to go because he sees where to go, he thinks about the speed of light which engraves the image of his direction on his retina.