The main layout configurations, in order of historical appearance
By JF Iglesias, FYN Surf Research and Development Manager
The SINGLE
To steer their longboards without daggerboards, surfers of the time (1930-1940) briefly dipped their foot into the water to turn the board. But the need for support to control the trajectory without skidding was very real.
The invention of the surf fin can be attributed to Tom Blake in 1934. The implementation of this fin revolutionized surfing by allowing previously impossible tricks, stabilizing the trajectory and providing better support on the rail, while creating a rear pivot for turning and changing direction.
But despite its indisputable effectiveness, this innovation proposed by Blake in 1934 was slow to be adopted due to its relative difficulty of implementation and the danger it constituted in the eyes of surfers of the time. The funny thing is that, with hindsight, this notion of danger has become natural, and soft-edged fins are abandoned by the vast majority of today’s surfers, who are more afraid of damaging their invincible warrior image than their unarmed bodies.
Aileron 1935
From 1935 to 1960, the height of the aileron continued to increase, and the fulcrum became more and more efficient, enabling ever tighter turns. The radical cut back and bottom turn are linked to this evolution.
Spoiler 1960
The 1960 single reaches a limit it can’t cross when it’s located in the center of the board: ventilation.
The TWIN
Bob Simmons proposed the twin in 1949 to avoid ventilation from short central fins:
With Simmons’ configuration, even if a fin comes out of the water and ventilates because of a very vertical wave wall, or a turn with a lot of roll, the underwater fin takes over, so you need a fin for the 2 sides of the turn encountered in the surf’s trajectories. The Simmons twin has an almost parallel layout. A slight toe angle takes into account the fact that the flow of water arrives sideways when surfing a wave in its vertical zone. Boards from the ’70s became shorter and shorter over time, increasing their maneuverability and making turns more radical. The turns generate a variation in flow direction on the fins:
No turn: direction towards the beach, water arrives parallel to the board’s axis. The surfer’s rotational movement causes the water to change direction on the fins during the turn.
The more radical the rotation movement, and the more vertical the wave, the greater the angle of the water arriving on the daggerboards. When the angle of attack of the fluid is too great, on a kite as on a surf fin, the efficiency drops abruptly: it’s the stall. The stall is most pronounced in the turning phase.
The solution to avoiding or postponing the stall is to reduce the angle between the water and the fin. This is done by setting the fin at a compensated angle for radical turns, the Toe angle (pinching the daggerboards that “squint” towards the front of the board). The Fish of the 70s, designed to play in small waves with radical turns, increases Toe angles, and moves the fin position forward to bring them closer to the surfer’s center of gravity and generate maneuverability. But this comes at the expense of stability, and becomes difficult to manage in larger waves where directionality is a guarantee of tranquility.
The THRUSTER
The solution to reconciling the handling pleasure of the twin with the soothing directionality of the single is provided by the truster configuration. This configuration has become widely accepted over the years.
But the drawback of a fin configuration with antagonistic toe angles is higher braking than with parallel toe angles.
On the Fish, a player in small, hollow waves, the good surfer takes the antagonistic fin out of the water as often as possible, and accepts braking 90 percent of the time on trajectories where he has both fins in the water, but as we’ve said, the Fish surfer is a player and isn’t looking for speed performance, he’s a skater.
For the thruster, it’s three different toe angles and the willingness to surf sometimes powerful and fast waves, performance degraded by fin braking with badly tuned angles can be a limit when the wave is very fast, big and throws its lip and the surfer behind on a coral bed.
QUAD
For demanding, high-level surfers, riding very hollow, fast waves, there may be an advantage in placing a forward fin close to the rail so as not to ventilate and to have maneuverability, and another fin close to the rail also so as not to ventilate, and with a toe angle relatively close to its front buddy to avoid creating too much braking. The side fin at the rear provides stabilizing directionality in powerful waves, where any mistake in trajectory is dearly rewarded! This configuration is advantageous for very fast, very vertical waves, requiring only two fins to be submerged, and the opposing fins to be out of the water.
This type of 4 fin configuration finds its application in exceptional waves surfed by exceptional surfers!
But it can also be used to create a twin configuration, which can be modified according to surfing conditions, and go from a twin Fish configuration with high toe angles and fins on the front, to create great maneuverability and a very playful character, and then switch to a Simmons-type twin with the fins set back and almost parallel, to offer a fast board in hollow waves. The slots will therefore be useful, but not all used at the same time. This is certainly the most useful use of this configuration for 90% of surfers.
FIVE
Like the quad, but with the option of a thruster or single configuration, this setup is perfect for surfers who want to test the best configurations to suit their mood and wave type of the day. The surfer who asks his shaper for this type of configuration has sunk to the experimental side of the forces, and will probably never be able to come back, because this quette has no limits!
The DUO
We’ve seen that the single configuration reaches its limit when the radicality of the turns or the verticality of the wave, combined with the speed of the section, require fins closer to the rail to limit ventilation and loss of grip. The duo configuration allows you to get closer to the rail so as not to ventilate when the center of the board comes out of the water, while keeping the fins parallel, so as not to lose speed due to antagonistic toe angles braking. By keeping the center of lift close to the center of the board, the bank effect is limited, and rail immersion is easier. This is an interesting configuration for relatively slow waves requiring a large fin surface, and a surfer wishing to push the rail hard into carves where there’s a risk of pulling the center fin out of the water.
The FYN LINE
When the single no longer offers enough lift in waves that open up without generating high speeds, a larger fin surface may be necessary. However, in order to maintain optimum rail support and keep the bank angle as low as possible, the fin’s center of lift must be centrally located. This configuration is only applicable with dynamic fins, which avoid blocking handling thanks to their adaptable dynamic Toe angles.
Now that we have an idea of where to put our fins, let’s have a look at their characteristics in a third part…
