Here is one way to install the centerfin box
And here's a third method to make the fin pocket applicable to wood or foam boards.
We have templates to make your own centerfin router jig at the bottom of THIS PAGE
Here is one way to install the centerfin box
And here's a third method to make the fin pocket applicable to wood or foam boards.
We have templates to make your own centerfin router jig at the bottom of THIS PAGE