Router depth for 8" center finbox?

First time routing a center fin for a 2+1.  I’m usign the Ryobi plunge router and the Futures One Shot install kit. But the kit didn’t come with instructions so I’m not sure how deep to set the router. Or actually HOW to set the depth on this router.  Anyone done this before and have some guidance?

On a work bench, turn your router upside down.  Use the fin box to set the depth by placing the box on the bottom of the router.  Then add the thickness of the “One Shot Jig”. If you are using your “One Shot Jig” to rout a Bahne/Fins Unlimited box, the depth will be the depth of the fin box plus the thickness of the jig…   The Bahne Box has a lip around the ooening that gets ground off so not counting that lip allows for the proper depth plus the thickness of the jig.  That’s the way I set my depth and therefore never need to use a tape measure.  You can always go deeper if you rout to shallow.  If you go too deep you run the risk of routing thru to the deck.  When shaping, I never shape my tails any thinner than one inch in the fin box area.

Oops!  It’s doubled up.  TOAD