Cappy,
The question was directed at Proud Mary but I see you've got a Prairie 29 too so your response is very relevant. The Prairie 29 in some ways is very similar to my Willard. I have 37-40hp, 2.57-1 red and an 18" prop. The Prairie needs more power so I thought it would require a bit bigger prop.
It looks like PM has the same make and model prop as mine. I used a cold galvanize coating the same color as his prop and rudder. But the last time I launched I just used ArmorAll like I'd used in Alaska. Trying to get a good idea how the two coatings compare re marine growth. The ArmorAll must have worked fairly well as we just made an eight day trip on the boat and if the performance was down it seemed very little. The hauling is something I almost must do but $300 for Prop Speed is not.