By what your calling a "bounce" I can only assume it is what's better known as porpoising. This is caused by an over-trimmed condition. The motor tries to pull the bow up and when it reaches its max the bow falls back down because the prop and lower are loosing bite on the water. Try adjusting the motor down a little at a time and see what happens.
A 6inch plate and some cheap minor prop work will fix that problem. Ive been working with a few duck hunters from arkansas and south Louisiana to remedy a few problems on those boats. ALso been doing a drag prop for a 40hp duck boat here and there.