what kind of rails i need in a 6 3 x 18.5/8 foe 6 to 9 ft fast wave

im planning to shape a 6 3 x 18 5/8 x 2 1/2  tail 14 inches  and nose 11.5 inches

 

i would like to use it in fast waves from 6 ft to 8 or 9 ft  ,

Truth be known, anything will work.     Hard down rail, or round 50/50.     The size range you described would be no problem, unless you are riding Pipeline, or some other similar wave.     Speed will be more a function of your rocker, and outline.

Down and under preferred.  Altough as Bill said; anything will work.  If you are a good enough surfer.

Spreckles to Brewer would work on that bat tailed single fin my friend or was it a 7 finned swallow tail?

thanks bill for you answer.

is not for pipeline , im travelling to costa rica and i would like to use it in wves like salsa brava and playa negra but i need a board that can hold easy in the pocket.

 

i think that 11,5 inches in nose and 14 in tail qith squash tail and concave to double concave can be good?

 

single to double creates nice lift and what are your rocker demension?

5 inches in nose and 2.3 inches in tail   and i like it flat in the middle