The optimal position and size of Coastal Boat fins

Share this Post

Whenever you are at a Coastal Rowing regatta, pay attention to the position of the fins. Each manufacturer has its own technique and preferences.  And if you think: “It doesn’t matter”, I’m sorry to tell you: you’re wrong.

The boat manufacturers always position the fin according to the characteristics of the water the boat is rowed in. So, if you choose a boat to row or even want to buy a new boat, ask yourself which size and position make sense for your area and intention. 

Default setting:

Usually, for Co2x a rule of thumb of 1.50m applies. This means that the fin is positioned about 1.50m away from the stern – 1.60m and similar distances are also common.
After discussions with manufacturers and rowers, we have compiled some facts about the position and size of the fin for you:

  • Fin position: The further towards the stern the fin is attached, the better are the gliding properties of your boat. The further the fin sits towards the bow, the easier it is to turn your boat. If you have a complicated triangular course with sharp turns a more central position makes sense. Long-distance races or marathons tend to require more gliding properties and a tail-facing fin.
  • Currents and tides: Large fins are more susceptible to currents. So have a look at the weather and the water before you make a decision.
  • Beach sprints: Small fins behind the stern are the best option for beach sprints. This race is about short, fast stretches, where as much gliding as possible is needed.
  • Touring: Here you are looking for a good general and straight-line stability. Speed is not the top priority. That is why a longer fin makes most sense for this kind of Coastal Rowing.

As with everything, the right compromise has to be found in the design and placement of the fin. Depending on the rowing area, there are also different fins for different purposes.

The optimal position of the fin: The different systems

Form and Position of the fin
  1. The length of the fin:  General rule: The longer the fin, the more directional and general stability. But with an increasing size cutting into the water, speed is also lost. From a pure resistance point of view, a smaller fin brings more speed than a larger one. However, a little fin requires additional strength (and ultimately speed again) when it comes to straight-line stability. I have to steer more and the boat is getting more unstable. A clever compromise is required here.
      • Long fin -> Directional stability
      • Long fin -> General stability
      • Long fin -> More resistance but less speed
      • Short fin -> Fast, unstable and less directional stability
      • Short fin -> Beach Sprint


  2. The size of the fin: The same applies to the size. Size and length should complement each other and be adapted to the specifics of the water – the larger the surface, the more stability and grip. The downside of a bigger surface is a slower starting speed and less manoeuvrability. Here too, a good compromise is required. Heavy rowers or touring rowers often choose larger fins, lighter rowers smaller ones.
      • Large surface -> Stability
      • Large surface -> Reduced manoeuvrability


  3. The thickness of the fin: Thinner fins can cut easier through the water and usually have a lower resistance than thicker fins. Downside -> depending on the material, you can lose stiffness and stability.

Our Tip:

Position of the fin while transporting a boat

Ask your boat supplier:

Most boat builders can help you with the fin. RUBENETTI and RS Boats can adjust fins for your specific needs. SWIFT offers fins to stick at your boat in different sizes. 


Share this Post

Subscribe to our Newsletter for more interesting posts:

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.

This might also interest you