Fins on a surfboard are far more useful than one might think. Why are these “pieces of plastic” under our board so expensive? What are the characteristics of a fin? Read on to discover more about the surf fin, and its role in the waves;
The basic parameters of a fin, and how it works:
The surface: More surface will bring more hold and control. Less surface will leave more freedom under the feet.
The rake (backwards curvature): More curvature will lead to longer curves. Less rake means more radical manoeuvres.
Base length: A long base will have great propulsion. A short base will be useful for short turns and more slack.
Depth (height of the fins): Depth brings more grip in the glide. Less depth will help for more release and speed.
Foil (aerodynamic shape of the fins edge):
– 50/50 = two symmetrical convex sides (central or rear fin of a quad)
– Flat = outside convex, inside flat on the sides, more control
– Concave = outside convex and inside concave, more lift, more speed
Flex (resistance to deformation): very flexible fins are often found on foam boards or beginner’s boards. This allows (in addition to avoiding accidents) soft support and high tolerance. High-performance fins often have little flex, allowing more control and responsiveness.
Cant (inclination of the lateral fins towards the rails): more cant allows good control of the turns on the rail but slows down the glide. And the opposite is true with little cant.
Taking into account these technicalities, you can start to imagine how it is possible to have very different glides with the same board – just by changing the fins. Each characteristic will be described on the website or the fins packaging, but it is important to ask yourself the right questions in order to determine which model will suit you.
1. Your weight?
Fins come in several sizes, often indicated in relation to a weight. You just need to know where you are located to choose the right size.
2. Which fins system?
There are several large binding systems, but you need to be sure of the one on the board for the fins to be fixed.
3. For which waves?
Large hollow waves will require more control, whereas for small summer waves, fins that allow more freedom in manoeuvres are recommended.
4. What style of surfing?
Do you prefer a relaxed style on the wave, or do you prefer performance in the radicality of the manoeuvres?
With multiple options available, it is easy these days to shop around, to find a model that suits you. If you have a reputable local surf shop or shaper, they will be able to advise you.
There are a wide variety of different and innovative fins available today. In our experience, we would recommend S-Wings, a French company who have developed fins with a continuous tail which twists during manoeuvres and allows a great propulsion when slackening. The fins can therefore fulfil very different gliding demands. To have even more choice, it is possible to change the layout and number of fins on the surfboard. We will cover these possibilities in another article.
Thank you for reading, we hope you have enjoyed the article, if so, please share, and feel free to comment, ask any questions.
