Repitching\cupping boat prop for lower plane speed

[lrdchaos]

I have a 5 blade 21 pitch prop that I run all the time for skiing, tubing, and just running around the lake, it works great. I have an extra 4 blade prop that I originally bought when I bought the boat. That prop is a 17 pitch, it tends to plane out at 18 mph, If I was to repitch it to a 15, would it plane out at a lower mph? I understand that it won't be able to run wide open, as it is now turns to many rpms on the top end. I'm not concerned about the upper rpms on this prop only, the hole shot and lower plane speed for wakeboarding. thanks in advance.

 

[rallyart]

Re: Repitching\cupping boat prop for lower plane speed

The boat will plane out at the same speed regardless of the prop. Weight and hull design determine that as it is the force of the water that lifts the hull. The only other thing that will change to planing speed is the attitude of the hull. That is changed by trim tabs or hydrofoils that can lift the rear of the hull or by placing weight in the boat forward or back. (eg. moving passengers to the bow)

 

[Bondo]

Re: Repitching\cupping boat prop for lower plane speed

Ayuh,... Great Big Trimtabs will lower planing speeds, Not repitchin' the prop...

 

[Bob_VT]

Re: Repitching\cupping boat prop for lower plane speed

You might also create a situation where you will allow the motor to over-rev. Yes, trim tabs would help.