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If you like to spend time by or in the water, you are not the only one. Research has found that just being by a body of water can boost your mental health and make you happier, less stressed, and more energized. You first need to know how boats work if you like to do various water activities, such as fishing or simply cruising in the river, lake, or sea. 

Some boats are made to get people from point A to point B more efficiently and securely. Such boats usually have powerful engines or boat propellers that will make them move faster without you having to row. If you are interested in buying a boat with a propeller or simply want to know how your boat works, you are in the right place. 

What is a boat propeller?

Boat propellers are usually found in the back of the boat and look like fans. Most of these propellers have different numbers of blades (usually 3 or 4) that rotate and push the boat through the water. Depending on the size of the boat, propellers can be powered by engines of different powers and sizes. You can get used boat propellers in good condition. Just ensure they are made from durable materials, as they can last for years of regular use.

  1. The materials 

The blades of boat propellers have a curved shape, and each can be made of different materials. Depending on the boat’s purpose, such as recreational fishing or transportation, the propeller’s blades can be made of aluminum, steel, or brass. 

When buying a boat propeller, you should consider your boat’s use. For example, aluminum propellers can be easily broken and dented, so they are suitable for still waters and waters that don’t contain many rocks. Steel propellers are made for rougher waters containing some hard objects since steel is harder to bend. 

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  1. The shape 

To understand the shape of boat propellers, you should keep two essential things in mind. A propeller has a curved edge with a leading and trailing edge. The leading edge, as the name suggests, is the edge that comes to contact with the water first, moving the water in the opposite direction. 

The trailing edge is a shorter part of the blade, and this is a place on the propeller where water leaves the propeller. The trailer edge creates a “hole” that is essential for moving the boat forward (we will discuss the purpose of the “hole” later on). 

How do boat propellers function?

A propeller rotates in the water, pushing the water in the opposite direction from the blades, which makes the boat move forward. We can compare boat propellers to rowing a boat – both instances push the water away from the boat, but the main difference is that the boat propellers do it faster. 

Engines usually power boats that have propellers. Here, the engine’s primary purpose is to power the propellers and make them rotate at certain speeds. When propellers are activated, the water pressure on the object in front of the propellers lowers. That’s why you usually find boat propellers in the back of a boat. 

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  1. Lift 

You may have already seen or experienced a propeller-powered boat lifting its front when the propellers are activated. There is a simple concept of why this happens, and it is powered by physics. When propellers move, they create a “hole” between two propellers that needs to be filled with water. 

When said “hole” fills with water, it creates pressure on the boat’s back end, making the front lighter, thus lifting the front. Almost every boat that has a propeller lifts up when the propellers are at work. 

  1. The pitch 

Another important term that can influence the performance of propellers is pitch. When a propeller moves, it pushes the water away from the boat at a certain distance. This distance is called the pitch. The performance of the propellers is usually characterized by the pitch they can create. 

Over time, the pitch may lower, causing your boat to move slower and have less power. Used boat propellers can have the same problem, so you must be careful if you buy a propeller with some miles on it. 

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  1. The pitch types 

There can be different pitch types, depending on the propeller manufacturing and the purpose of the propeller. If you are using a boat for recreational purposes, there might be a chance that you are using fixed-pitch propellers. 

Fixed-pitch propellers are permanently attached to the hub, moving at the same speed when activated. You cannot change the pitch while the engine is running, and your boat will always have the same pitch. 

On the other hand, you can also come across controllable pitch propellers. As the name suggests, you can always adjust the pitch you want your propellers to have. This propeller type is mainly used for larger boats and ships because the pitch can be determined according to the ship’s weight, making it stable and secure. 


The science behind boat propellers may seem complicated, but this is not true. Above, we have explained what boat propellers are and how they function. If you want to buy your first boat or learn more about how boats work, you are in the right place. Before deciding, you should check what type of propeller you need based on how it functions. 

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