A basic boat prop has multiple angled blades extending from a center point. The center point attaches to a shaft connected to a gas engine. The prop resides just under the water line. As the boater starts the engine, the prop will begin to rotate in the water. The rotating blades create turbulence with the water that pushes the water away from the blade assembly. As a result, the boat moves forward and gains speed.
Overall, the best boat props are constructed of stainless steel, states Popular Mechanics. Stainless steel offers resistance to corrosion and resistance to damage from use. Thin blades can be constructed with strong steel material as well, contributing to an overall lightweight prop assembly. One negative aspect of stainless steel is its cost. Stainless steel boat props are the most expensive of all. Other materials are available in the marketplace, including aluminum, composite and plastic.
The diameter of a boat prop measures the distance between opposite blade tips. The best prop size depends on the boat's size. A smaller boat does not require a large push from the propeller blade, so a smaller diameter prop is a practical match. In contrast, a larger boat needs a wide prop for strong maneuverability through the water.
Pitch is a measurement of how far the propeller moves forward as the blade assembly completes one revolution. In general, a low pitch value, such as 19 inches, provides pulling force more suitable for boating sports such as water skiing. A higher pitch value, like 23 inches, is well-suited for a light fishing boat adventure at cruising speed. Overall, the best boat prop pitch depends upon the boating application, whether high speed is needed or a low, cruising speed.
