All bows used for bowfishing need to be bare shaft tuned to get the straightest flight possible and with most longbows, they are not cut to center. I have had to shorten several fiberglass shafts to get them to spine properly off some heavier poundage recurves, but with most around the 50# range, they fly great full length. Tune them just like you would for hunting and see what a bareshaft with no line attached flies like and adjust the length if they are excessively weak. Good luck, Mark
Or just holler at me here at Muzzy and I will be glad to help, straight shaft flight is very critical with bowfishing arrows as it is with hunting shafts!