Factors that Affect the Selection of a Boat Prop
You should settle for the right boat prop when you need your boat to work properly. This means you need to pay special attention to the prop size, number of blades, the material used to make it, its rpm at wide open throttle, and the functions of the boat.
The prop size is a critical consideration. By choosing the wrong size, you shall inflict damage on the boat and the engine. You will also damage the ventilation and cavitation. The prop’s diameter and pitch determine the size. These are normally stamped on its hub. The first digit is for the diameter while the second one is for the pitch. Should the boat be powerful enough, the higher pitch would boost its speeds considerably. A larger diameter would then mean the boat gets to accelerate much higher.
A prop can come with three to five blades. A prop with more blades tends to perform better. Racing boats rely on three bladed props for their top-end speed. Cupped blades are even more preferred. Cupping refers to the curve at the end of the blade. This is what will keep ventilation at bay and help make the boat turn sharply. The rake of the blade is also an important consideration. The angle of the blade with the propeller hub affects the boat’s performance.
You will also have to look at what material was used to make the prop. You will have an easily accessible and affordable option in aluminium. It is lightweight, but will keep the boat safe in cases of obstacles. It is however not resistant to rust and salt water. You would need stainless steel for that, but be prepared to pay its higher price. It will be there for longer and take in all that salt water throws at it. It will, however, cause damage to the engine in case you hit an obstacle. Do not forget about a composite and plastic prop for emergencies.
As for the rpm at the wide open throttle, there is a specification for each engine. This is what will guide you when you are making your choices.
You also need to think of your purpose for getting the boat. There are props designed for different types of boats, such as pontoons, bass boats, as well as those meant for skiing, fishing, racing or leisure. You need to also think of the water on which you shall use the boat. There are always those meant for the lakes, rivers, and other slow waters. Others are designed for the high seas. There are also the flat heavy boats used for transporting passengers and goods. You will also see those meant for high performance such as for racing.
These are the factors that shall help you pick the right boat prop.