The leading edge of the fin is where the foil actually starts.
The tab that extends forward of the leading edge is only the mounting point,
so I'd put the junction of the front edge of the actual foil to the mounting tab on the recommended settings, not the front of the mounting tab.
The marks are pretty much a guideline or starting point. You can tune the board fin combo from there to suit your conditions and sailing style.
Hope this helps,
|