If you are looking for a boat propeller then you will need to look at two main factors and they are the size of the propellers as well as the power of the engine. Once you are able to look at these things then you can get the optimum boat performance and the fuel efficiency all at the same time. Aside from these two main factors. It is also your that will need to look at some other factors as well. Read more about
One of the factors that you need to consider when choosing a boat propeller is the diameter and pitch. The diameter is the circle made by the rotating blades. The pitch on the other hand is the distance reached by the boat on each rotation of the blades. You need to make sure that the pitch will give the boat maximum momentum. What you need to do though to determines the ideal pitch and diameter is to look at the specifications of the engine. Most manufacturers will be providing you with the right pitch and diameter measurement. Check out the Propeller Depot
at this link to get started.
Another thing that you also will need to look into on a boat propeller is the number of blades that it will have. You will most likely find blades that will have either three or four blades. A four-bladed propeller is the one that can provide you fast here, quick acceleration, fast here planing, higher transom height, less slippage, and better holding power. If you are also looking for better top speed which you can use for racing then the three-bladed propeller is what you should be choosing. It is also you that will have to look at the cupping of the blades. It is this one that refers to the curve at the edge of the blades. The more cupping the blade will have, the better the grip it will have on the water. Another thing that you also will need to look into is the thickness of the blade. In order to reduce drag then you will have to choose the blade that will be thin enough but also have the strength to endure usage.
It is also important that you will be looking at the materials that the propeller is made of. It is important that it is made from durable and noncorrosive material. If you are using the propeller in lakes then you should choose the aluminum ones. If you are looking to use it on slat water then a stainless steel one is your best bet. Although stainless steel propellers cost more but they are the also the ones that can last longer.
For more info, check out http://en.wikipedia.org/wiki/Propeller