Fin Talk:
A Guide to Choosing the Right Single Fin for Your Longboard

words by aske foyd | illustrations by Christina Sierra

As the winter storms fade, the swell period drops, along with size, and we are forced to opt for longer boards with more foam and glide.  Luckily, we start getting small but organized south swells that light up some of our favourite longboard spots.

As we head into this season, you might find yourself buying your first log.  You also might find yourself thinking about last year's summer season, wondering if you can fine-tune your set-up.  A fin can completely change the performance and personality of your board. 

We have written this article to help guide your understanding of longboard single design and various fin styles.

Before we dive into the various types of longboard fins, we have to cover two fin design points: fin depth and rake.Fin depth is measured from the tip of the fin to the base of the fin vertically when it is in a board.  This is the most common measurement and is used to list fins on our website. 

The deeper a fin, the more hold it will have.  A deeper fin can especially help with hold when you are on the front half of the board noseriding. However, various fin templates will have more or less hold depending on the surface area of the fin. For example, a 9" pivot style fin will have more hold on the wave face than a 9.5" flex fin. 

Because of this, there is no exact, universal formula for what size of fin to choose for a board.  An easy way to start on your fin journey is to choose a fin that is the same depth in inches as your board is long in feet.  When in doubt, round up to the nearest half inch to make sure you have enough fin for your board.

A Quick & Dirty Breakdown to Single Fins

D Fin

The D-fin is a classic fin template from the days when longboards were the only option, even for big wave charging in hawaii. The name is self-explanatory and this template creates an incredible amount of hold due to ample surface area.  However, because of this extra surface area, water moves around the fin incredibly slowly, slowing down the board. 

Because of being sluggish, D-fins are best suited for fast lined up waves to provide the push required. D-fins have shallower fin depths, making them tough to nose ride.

Flex Fin

The narrowest tail variation, where the back of the surfboard meets at While not having much fin rake, the flex fin still thins out to the tip of the fin. This upright design combined with less surface area makes the flex fin very sensitive. 

This sensitivity allows for more radical maneuvers and can really liven up a board.  However, with the lack of surface area, especially at the base, it can be hard to generate drive.  Because of this, flex fins shine in better, lined-up waves that give you all the speed you need.

True Ames 8.75 Furrow Labyrinth Single Fin →

Hatchet Fin

Hatchet fins are characterized by a lot of surface area at the tip of the fin, with reduced surface area in the middle of the fin. This allows for a fin that acts like a D-fin, but with more fin depth and turnability. 

The middle section of the fin can flex and twist giving more forgiveness than a D-fin, especially in variable conditions.  The extra fin depth also helps with hold when you are headed to the nose.

Pivot Fin

A pivot fin usually has a fair amount of surface area and are pretty upright, without much rake. The depth and surface area of these fins make them great noseriders. As the name suggests, these fins are suited for snappy pivot style turns where you stomp the tail to turn and set your line before running to the nose. 

Because of the lack of rake, these fins aren't as useful in variable conditions or doing longer, drawn-out turns.  

True Ames 10" Troy Elmore Pivot Fin →

All-Rounder Fins

A great place to start is a fin with a blend of all of these attributes. One of our most-popular fins in this category is the greenough 4-A.  This style of fin does a great job of pulling aspects from each of the above single fin styles.  Surface area in the base of the fin for stability and to give the surfer something to generate drive off of.  Thinning out to the tip of the fin to allow for more release and turnability, while keeping more surface area and rake than a flex fin. 

This combination creates a great all-rounder that should definitely be in your collection.  This fin style is especially forgiving in variable conditions and with newer surfers.

True Ames Greenough 4A Single Fin →

In summary, consider the type of longboarding you want to do as well as the types of wave you'll be surfing in when picking a single fin.  When you get a new fin, make sure you try moving it around the fin box to find the sweet spot.  The further forward in the fin box, the looser the board will feel.  The further back, the more stable the board will feel.

If this article sparks any new questions, give us a ring at 250-725-3344 or an email at for even more info on your next fin!