Trolling Motor: Shaft Length Guide
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Looking for a durable trolling motor for your boat? Check out our complete line of trolling motors with shaft lengths ranging from 24" to 40".
Choosing the correct shaft length for your trolling motor is important for several reasons. First, it is important to ensure the propeller remains beneath the water line to provide optimal thrust. Opting for the longest shaft may seem like an easy solution, however, this can cause your motorhead and propeller to make contact with rocks, weeds, logs, and other underwater hazards. Longer shaft lengths also result in increased drag, which reduces the performance of the motor. Ensuring the correct shaft length helps avoid noisy cavitation bubbles, which spook away fish. Below, we detail the recommended steps in choosing the right shaft length for your needs.
Measuring The Shaft
The shaft length on a trolling motor is measured from the base of the motor head down the the top of the motor compartment.
Transom Mount Motors
In order to get the correct shaft length needed for your boat, you first have to measure the distance from the mounting spot on the transom, down to the waterline. Then, take this measurement and add 20” to get the desired shaft length. If you are stuck between two sizes, err on the larger size. You can’t make a short shaft longer, but the longer shaft can be adjusted. If you are in rough water more often, we advise adding an additional 5” onto the total shaft length.