The selected boat propeller determines how well a boat shall perform. There are a few things that govern your propeller choice. You need to think of 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 emerges as the most important consideration. Choosing the wrong size leads to damage to the boat and its engine. You thus have to consider the boat prop’s diameter and pitch when measuring its size. The higher the pitch, the more speed the boat shall manage, given it has a powerful engine. Larger diameters in the other hand give the boat faster acceleration.
The number of blades also varies, between three to five blades. The more the number of blades, the more performance it can deliver. Lesser blade numbers have been known to lead to the highest top speed. This is why racing boats go for three bladed props. If it is cupped blades, even better. Cupping is the curve at the end of the blade, which aids the boat in making sharp turns. There is also the rake of the blade to think of. The angle between the prop hub and blade is the rake. Its the purpose is to prevent slipping.
You need to find out what material was used to make the prop. Aluminum props are easily found and are cheaper. They make for lightweight and strong props. They, however, cannot survive in salty water for long. You would need to go for stainless steel there. You will have to spend more on those blades though. They also present the danger of damaging the entire engine system, which is not the case with aluminum props. You will also find composite and plastic props, which are ideal for emergencies.
When choosing the ideal RPM rating, you need to look at what is recommended for the boat. You only need to read about it in the manual to make the right selection.
You need to also factor in the use of the boat in your selection. You shall find a wide variety of props, each serving a specific purpose. You shall find some designed for pontoons, bass boats, and skiing boats, those for fishing, racing, or relaxation. There is also the thought of the kind of water the oat shall be traveling on. Props used on lakes, and on rivers, and even on slow moving waters are not the same. You will find a selection meant for the high seas. Some are specially designed for flat, heavy passenger or goods boats. This means that your choosing has to consider such differences. It is also important that you buy an extra prop in case of an emergency.