I think I would feel better springing for a steel prop. I could see hitting a rock and ripping the skeg, and maybe the foot housing. I have hit a lot of stuff with a steel prop and suffered no damage.
The best thing to use was never meant for use on a boat motor .....a pitchfork tine , remove the long wooden handle and mount on the motor foot (weld or large hose-clamps), keeps weeds/hydrilla out and you can even run over logs & rocks with no damage to the blade....mount on the front side (leading edge) of foot, it will protect both the blade and the foot..... curved backwards of course.