Propeller Pitch: What Does It Mean?
One of the most important propeller specs for boaters to understand is pitch. Propeller pitch is the second measurement listed on prop specs, and is measured as the distance (in inches) a propeller will travel while completing one full rotation. For example, a 13.5” x 16” 4 blade propeller it will travel 16” in a single rotation.
By increasing the pitch greater top speeds can be accomplished as the boat will move forward through the water further with each rotation. Boaters looking for higher speeds for waterskiing, barefooting, or cruising across the lake will benefit from this performance characteristic. The down side is a loss of power at the low end, commonly known as hole shot, which is the time it takes for the boat to accelerate from a rest to the desired operating speed. If you're pulling a surfer, that time may not be very long, but if you're pulling a wakeboarder, or slalom skier, it can easily stretch out into 20-30 seconds if you have the wrong prop, which is not a desirable experience for the boat driver, or the person at the end of the rope.
Most wakeboarders and wakesurfers are looking for the opposite affect and choose a lower pitched prop. By lowering the pitch the boat won't travel as far forward with each revolution, but the engine will have an easier time rotating the prop which results in better acceleration to the desired speed when loaded with more ballast weight or at higher elevations when HP is decreased. The downside to decreasing the propellers pitch pitch will is the accompanying reduction in top speed of the boat, although for most watersports enthusiasts this is a trade-off they are willing to make.
Think of pitch as the gear you want to start in when driving a car. If you have a higher pitched prop you are starting out in third gear which means you will be able to drive faster ultimately, but it will take you longer to reach that point. If you choose a lower pitch that is similar to starting out in first gear; you'll get great acceleration from a stop, but the maximum speed you can achieve will be significantly lower.