For someone who is new to the world of boat props, the terminology used in describing various types and parts of boat propellers can be quite confusing. Given below is a brief description about various terms that you might come across in trying to find yourself a suitable boat propeller.

The parts of a boat prop: The normal boat propeller is made of either three or four blades which surround the hub. The hub, in turn, connects the blades of the propeller to the engines drive shaft. The blades are angled in the way that enables them to screw through water, thereby moving the boat ahead. The leading edge refers to the end of the blade that cuts through water, and the opposite side is referred to as the trailing edge.

The drive shafts teeth are referred to as splines, and these arent part of the propeller itself. A hubs design ensures that it fits into a drive shaft keeping in view the number of splines it has.

Various Features: A boat propeller is mainly classified depending on its diameter as well as pitch, and this is normally embossed on the hub in the form of two numbers (in inches). While the first refers to the propellers diameter, the second refers to its pitch. The diameter of a propeller is the distance from the end of the blade to the center of the hub. The pitch is used in referring to the distance that can theoretically be traveled by the propeller in one revolution. The reason that a pitch is referred to as a theoretical representation is because it can experience slips in different scenarios. Slip refers to the ratio between the actual distance traveled and the props pitch. The slip could be different under similar environments; for instance while a work boat might experience a 60% slip, a well kept private boat might experience a 15% slip in exactly the same weather conditions.

The rotation can be either left or right hand. A majority of the boat props have right hand rotation. You can expect to find a left handed one on engines wherein double engines are needed to counter the motors torque which can lead to pulling the steering in one direction.

Cupped blades refer to blades whose angles have been specially treated and their trailing edges are further curved. This is done because it increases the props performance under specific circumstances.

The rake refers to the blades angle from the hub. A negative rake indication shows that the blades are pointed forward (towards the boats front), and this is generally done to strengthen high end props.

Before you start, it is important that you note down your engines specifications, such as make, horse power (HP), model, etc. and your existing props details like its material (steel, aluminum, etc), diameter, pitch, and number of blades. You can then comfortably embark upon your hunt for a new boat prop.