How to Install a Fin in a Standup Paddleboard

Installing a fin is really pretty simple when you know which way everything goes. The most important thing to note is which direction the fin faces… the top points towards the back end of your board.

The fin slides into a box (called a fin box) that is already installed in your board. The fin box has a track that holds a square washer or screw plate that, in turn, holds the fin in place. The track allows you to slide the screw plate (and thus the fin) forward and backward in the fin box.

What do you need?

  • Fin
  • Screw
  • Screw plate or square washer (it has to fit in the fin box and slide along the track)
  • Screwdriver

Let’s install that fin

Start by sliding the screw plate into the fin box. There will be a notch or wider area of the fin box where you can insert the screw plate so that it slides along the track in the box.

fin box 

Use your screwdriver to slide the screw plate to the end of the box where the plate will line up with the hole in your fin.

insert a fin

Next, take the end of the fin with the little metal tubes (this is the back bottom of the fin) and slide it into the fin box. You’ll put the part with the tubes into the notch first and slide it back. The tubes will sit in the track in the fin box just like the screw plate does.


If the plate is not lined up with the hole in the fin, use your screwdriver to move the plate, and then drop the screw into the hole in the fin.


Start turning the screw, you should feel it catch the plate and start tightening the fin into place. Thread the screw into the plate firmly. It does not have to be Hercules tight, but definitely snug.

That’s it. You have installed your fin! Double-check to make sure you can’t pull it out, or slide it back and forth.

The position of your fin will alter the way your board handles when paddling in a straight line or turning. Experiment with sliding the fin forward or back to find the position you like the best.

Don’t sweat–putting a fin in is easy!