When it comes to “proper propping”, there’s no magic bullet or one particular prop that perfect for all boat types and engine applications. This is due to the extreme and varied conditions under which a boat and propeller must perform. For instance, the surface drag that a boat has places a great load on the engine (that’s why a boat slows down so rapidly when you reduce the throttle). Among other things, that load varies by the type of boat, the hull condition, the boat’s overall weight at any given moment, and the horsepower and engine style being used to push it.
Because of factors like these, it’s very important to find just the right prop so that the engine and the boat perform properly, and each application is different, which is why there are so many different kinds of props. But don’t despair, there are proven ways to ‘hone in’ on the right prop for you.
As a general rule, the correct propeller will allow your engine to reach the upper portion of the WOT (wide open throttle) range specified by the manufacturer without exceeding it, with a normal-to-heavy load. For example, if your outboard says WOT is 5000-6000 rpm, you need a prop that will allow your engine to turn between approximately 5700 and 6000 rpm with your average-to-heavy load in the boat. Be sure to account for things like fuel, full bait and/or live wells, batteries, passengers, and all gear, including safety gear like anchors, ropes, etc.
This chart serves as a very general guide in selecting the correct propeller family, or style, for your particular type of boat. While this will help you get started, we suggest seeking the input and advice of your local Turbo propeller dealer when picking your next prop. They’re a wealth of knowledge and assistance.