Having some problems with making a rocker

Im making a 6’0 fish. It will be 2.5" thick, and 21" wide. Im confident in shaping it, but i have no clue how to make the rocker. I want it to be really mellow, but im unsure about measurments, and cutting it. Sorry to sound stupid, but im new to this and really excited about doing it. So i would greatly appreciate some help.

Thanks alot

Clark blanks come cut with correct rocker.

If you are doing epox styro, you are in over your head.

Gotta learn somehow right? Any tips? Should i cut the rocker out of some plywood and try to follow that?

cut your intended rocker curve into your stringer and then glue the foam to that.