Surfboard fins and their set-up on a surfboard are often afterthoughts for many surfers. As a beginner, it's truly something not to worry about. But as a progressing surfer, it's something that should be increasingly considered. Although there are numerous setup possibilities, the main focus should be on their combined surface area and their placement on the board. The surface area of the combined fins - affects the way the board feels and dictates its responsiveness under your feet. More surface area, increases control and stability, but slows the board down and stiffens it up. Less fin area does the opposite. When considering fin placement and if you're looking to make tight, hard turns, fins placed closer to the centre of the board (lengthwise) in a more forward position, will enable an easier turning arc yet control will be sacrificed. Likewise, if you need more control, a board with fins placed closer to the tail will make turns more drawn out and the board will feel stiffer.
Single fins are largely found on longboards. They're largely suited for down the line surfing, rather than top to bottom surfing. Ideal for walking the board on a 9'+ board single fins offer stability when it's needed. They can also be found on other retro shapes in shorter lengths that are suited for a more old school cruisey way of surfing, using the waves energy rather than generating it from a heavy bottom turn accustomed to a more new school way of riding.
The twin fin setup took over from the single fin - and presented a new level of performance surfing. At the time, it added about 25% more speed to the single fin, but tended to spin out on fast turns. In hollow waves, only the best surfers can ride a twinny - as it has limited holding power when banked on a rail. Instead it performs really well in mediocre fatter waves where down the line speed is of the essence. In today's modern surfing, twinnys are usually seen on a fish surfboard, ideal for waist to shoulder high sloppy surf - where they generate speed easily and give a lively feel in relatively poor conditions.
By far the most important and certainly the most popular fin setup in the world, the thruster lends a stable feel to a manoeuvrable board. Not only is it seen on the majority of boards, it's also the trusted set-up for the best surfers in the world and still remains the industry standard. Simon Andreson, who is credited with the design, combined the speed and liveliness of the twin fin together with the hold of the single fin. You have all three fins working together to give you the best all-around ride.
The quad set-up is probably the most under rated fin set-up available on the market. Most surfers have never tried, or haven't given one a fair chance - probably due to too much stigma, or the fact that their local shaper doesn't particularly endorse the set-up and hasn't truly figured out the blend of fin size together with their placement on the board. But let's just consider some of the facts. Four fins are faster and looser than tri fins. They ride the barrel higher and tighter, they drop in easier and they come out of the gate quicker. They accelerate on cutbacks, do better airs and can be ridden shorter. Riders can draw new and different lines and they're superior in larger surf. So why aren't more surfers riding quads? Perhaps it's to do with the control that a thrusters offers. Quads take time to adjust to and for many 3 fin surfers the adjustment period is too long or the transition just too large. We also suspect that many surfers tried a quad before the real progression had been made with the finer tuning of the set-up. The early beginnings probably lead to mainstream views that the 4 fin surfboard was only for the experimental surfer rather than something that could be the new industry standard. We believe the 4 fin (or the 5 fin) could well be the set-up of the future. Don't write it off just yet, but instead, search out a shaper who embraces the design and has a history with the setup.