your propeller choice has a lot of significance to the boat’s performance. When choosing a boat propeller, you have to keep certain things in mind. These are its size, number of blades, the material it is made out of, its RPM at the wide open throttle, and the use of the boat.
The prop size has been found to be the most important thing one thinks of. Choosing the wrong size often leads to a damaged boat and engine. You need to look at the boat prop’s diameter and pitch when gauging its size. The higher the pitch, the more speed the boat shall manage, given it has a powerful engine. Its larger diameter means it will accelerate faster.
There are props with three to five blades. The more the number of blades, the more performance it can deliver. The fewer the number of blades, the more top speed it can achieve. You will thus see most racing boats with three bladed props only. If it is cupped blades, even better. Cupping points to the curve at the end of the blade that helps the boat make sharp turns. There is also the rake of the blade to think of. The angle between the prop hub and blade is the rake. It aids in minimizing slipping.
The material used in making the prop matters. Aluminum makes for cheap props that are easy to find. They are strong and lightweight. They are however not good for use in salty water. Stainless steel props are the better option there. Those are not as cheap. They also present the danger of damaging the entire engine system, which is not the case with aluminum props. You may also come across composite and plastic props, which are useful in case of an emergency.
When choosing the ideal RPM rating, you need to look at what is recommended for the boat. There are manuals from which you can refer for more info on this.
The purpose of the boat is the other factor you need to consider. There are many prop types out there, meant for different uses. There are those meant for pontoons, bass boats, and skiing boats, those for fishing, racing, or relaxation. You also need to think of the water on which the boat shall be. Props used on lakes, and on rivers, and even on slow moving waters are not the same. There are those which are ideal for high seas. There are those for flat, heavy passenger boats. There are all manner of uses for these props, which must be factored in the purchase. You should also get an extra prop, in case an emergency comes up.