Of all the bowfishing I have done, I never once considered trying to tune the arrow or matching draw-weight to the spine of a fishing shaft. I do remove the rubber fletching to eliminate steerage (rudder).

Considering that the arrow is in the water, or partially in the water, within a few feet, it has always been my thinking that trying to obtain good arrow flight and hunting or target accuracy with a long and heavy fiberglass fishing shaft would be a practice in futility.

I shoot off a 45# and 48# recurve and a PSE "Pacer" compound set at 50#, and have good results.