A tire is to your car as a fin is to your surfboard. Your surfboard fins connect you to the wave, dictate how your board will handle and are an incredibly important part of surfing.
Yet, few surfers – even very experienced ones – seem to pay attention to their fins. To help you choose the right fins for your surfboards and for a given wave type, this is Surfboard Fins Explained.
Hello and welcome to Benny’s boardroom! I hope you’re doing well, I hope you’re getting out and getting lots of waves. Today, we are going to talk about surfboard fins. Fins are a really important part of surfing. A fin is to a surfboard as a tire is to a car. You wouldn’t take the tires off of a Formula 1 race car and put them on your family wagon and try to drive it to the supermarket and vice versa. It just wouldn’t make sense. So, there are fins that are better for certain purposes and we’re going to talk about the basics of fins today so that the next time you’re shopping for fins to put on a surfboard to go somewhere you will be better informed. The three basic elements we will cover about fins are the:
- Surfboard Fin Template
- Surfboard Fin Foil
- Surfboard Fin Flex Strength & Pattern
The template is what surfers pay most attention to because it is what you can see easily. Regarding the height of the fin and the area of the fin, think about this like a T-shirt size. If you are a bigger guy or a taller guy, you’re probably going to wear a large or an extra large T-shirt. In general, you’re going to want a fin that is a little bit taller and has a little more area so the fin will sit deeper in the water and it’s going to keep your board in the water while you are surfing if you are a big person. At the base of the fin, this width is called the fins ‘base’.
A wider base gives you more drive. Drive is the dynamic similar to what you might feel going around a sharp corner in a high performance car. You slam the accelerator right as you come around the corner and the car pulls through the turn: that is drive. That’s what a wider fin base is going to do for you.
The rake is what’s going to give you more or less pivot while turning. If you have a greater amount of rake you will want to make longer, more drawn out turns; better for a fish or a single fin style of board. If you want to make really sharp turns you’re going to want to have less rake.
- More Rake = More Drawn Out Turns
- Less Rake (more upright) = More Pivot, Sharper Turning Radius
The second thing that is important to think about when you talk about surfboard fins is the foil. The dynamic of foil is similar to what you would see on an airplane wing. You will see that the profile of an airplane wing goes from thicker to thinner on top of the wing. What that does scientifically is to cause air molecules to go faster over the longer part, slower under the shorter part and that creates lift. This is a similar concept when you are talking about the foil of a surfboard fin. Less foil means that the fin is generally going to control speed better but if you have more foil in the fin then it’s going to help you to generate speed. So, having more foil, or more of a bow in the fin, will help you to generate more speed and transition rail to rail more quickly.
Fins with more foil are generally better suited for smaller, weaker waves. Conversely, less foil or a flatter foil is going to help you to control speed, so fins with less foil are better suited for bigger, better waves because you don’t need to generate speed so much as control speed.
- More Foil = Generate Speed (better for smaller, weaker waves)
- Less Foil (flatter foil) = Control Speed (better for bigger, more powerful waves)
The third important element of a surfboard fin ‘Flex’. Flex is basically how the fin moves laterally. Surfing bigger, more powerful waves, you’re going to want those fins to be holding on a steeper drop so you will want to have less flex. Conversely, if you’re surfing a bigger, thicker board such as a fish and in slower waves, you might want to get that fin be a little bit more flexible so that you get in a little bit more spring out of turns.
- Less Flex (stiffer) = better hold in bigger surf
- More Flex (less stiff) = more spring out of turns in small surf
Again, the three fundamental elements of surfboard fin design are the Template, the Foil and the Flex. Here are some examples:
The AM2 is more upright and is generally for better waves. The base is a little bit narrower, the rake is a little bit shorter and a little bit narrower up the top so this is going to pivot in better waves. Also, the foil across the bottom is relatively flat so, again, this is a fin for good waves, good for controlling speed, not as good for generating speed. Th FCS H3 Nexus is quite the opposite. It has quite a wide base and you can see that this is big and wide going all the way through to the tip. This is going to provide a lot of drive and it’s going to be quite flowy. It has a bit foil as well so this is going to generate speed and go rail to rail more easily. This would generally be better for smaller, weaker surf.
That is surfboard fins explained. I hope this is helpful to you and that the next time you go and buy a set of fins you don’t just buy a set because they look good but also because they will suit the type of waves you will surf!