I agree with Bulz. Try shooting instinctive when bowfishing.

I use a compound, but with no sights. Bowfishing is usually a sport of super quick shots at unknown distances and unknown depths. Trying to use a sight just slows things down. (in fact using a compound slows things down)

You'll be suprised how fast you can become good at instinctive shooting. Really.

(and then... if you miss.. you'll have a good excuse too)