Best way to sand base of big glass-on fin to fit rocker

Going to be glassing on a big fin to my noserider.  Bought the fin(“Full Pivot” from Rainbow Fin Co.), and the bottom is totally flat.  My available options are hand tools(sand paper and blocks) or a small table top belt/disc sander.  Any tips on how to get the base of the fin to match up with the tail rocker or(as I suspect), is it just “do it man!!  just eyeball it!!”??  Thanks.

1)tape fin in place

2)take a pencil and lay it on its side on the bottom of the board. run the pencil along the bottom and it will make a line on the fin that follows the rocker’

3)clamp fin on its side on a table and use the grinder to sand in the curve.

Lots of ways to do this but you get the basic idea.

Thanks.  Sounds like a plan.  

Glass on after bottom lam, BEFORE hotcoat, right?

 

Yes.       Also, the technique described by Cleanlines is quite sound.     Follow it.

Thanks Bill.  Much appreciated.