A good trial or error?

I’ve been reading a little about 3 stage rockers and and want to try to use it on my next board. The dimensions are 5’11 / 18 1/2 / 2 1/16 semi-flat deck with boxy rails. I’ll make the center of the board totally flat with the rocker coming up at the first and last foot of the board. Do you think this will work in knee to chest high surf? Or if you think I should just use the blanks rocker ? Any advice would be cool thanks, My ability is pretty good.

                               Da Cheetah