What pitch of prop should i use for speed on a 18ft boat?

Question

What pitch of prop should i use for speed on a 18ft boat?

Answer 1

It's dependent on the boat model and propulsion unit.  Ask the manufacturer. You can use trial and error but you will have a lot of props you don't want with difficulty finding a buyer to take them off your hands.

Answer 2

There is way too much left unsaid in your opening question. I don't know how much that you know about boats or props, and with not knowing the details I will at least give you some basics.

In general to increase top speed you would "step up" your prop. For example if you are using a "19" pitch prop now then you would increase the number IE: "21". This will decrease your ability to "plane out" as easily and the low end power will be diminished IE: pulling water skiers out of the water, etc. A stainless steel prop will help with overcoming the plane out/low end issues. Another consideration would be to do a gear change in the outdrive (assuming that it is an inboard/outboard etc.)  The actual answer to your question is more detailed and needs more information to be able to really come up with a solution that will come closer to what your desire is. Happy Boating!

Answer 3

This is a wide open question, but I will try to give you some insight. First of all you will have to get several props with different pitches and just try each one out. Start close to the pitch you have on the boat now and work from there. The main thing you need to watch are your RPM's. You do not want to exceed manufaturers recommended RPM's for your engine. Running at the edge of the Max RPM range will most likely shorten the life of your engine. By adding top end speed you will lose your hole shot. So pulling a skiier or any other wakeboard, tube, etc, will be more difficult to accomplish.  Talk to your local dealer for your engine and they should have a prop chart that will help you get started in the right direction