What Is The Ideal Trolling Motor Shaft Length? (Detailed Guide)

Each of the parts of your boat requires special care and attention. Without a motor and shaft, you will be left to paddle and move slowly through the water. So, what is the best trolling motor shaft length?

The best trolling motor shaft length for most boats is 36” to 60”. Bow mount trolling motors require shafts that are at least 36” long, but they can measure up to 72”. The average 150-horsepower pontoon boat needs a trolling motor shaft that is at least 60” long to achieve 40 pounds of thrust and minimize drag in the water.

Check to see if the shaft is too long when you idle in calm water. This will tell you if you need to shorten the shaft to avoid dragging and hitting debris in shallow water. Follow along as we explore the ideal trolling motor shaft length.

Bow Mount Trolling Motor Shaft Length

The ideal trolling motor shaft length depends on the space between the bow of the boat and the waterline. For example, a 36” shaft is the perfect trolling motor shaft length if the space between the bow and waterline measures 10”. Many boats with trolling motors have a 16”-44” gap between the bow and waterline.

In that case, the ideal trolling motor length is anywhere from 42” to 60”. You can even find trolling motor shafts as long as 72”, but those aren’t necessary for most boats. Those are primarily useful if the bow to waterline gape is over 45”.

Transom Mount Motor Shaft Length

The ideal transom mount trolling motor shaft length is 42”. That’s because most modern fishing and cruising boats have gaps between the transom and waterline that measure 16” to 22”. However, you only need a 30” shaft for your transom mount trolling motor if there is 10” or less between the transom and waterline.

Choose a 36” trolling motor shaft for your transom mount if the transom-to-waterline gap measures 10” to 16”. The most important rule is to make sure that the motor sits at least 12” beneath the water. If the shaft is too short, the motor may stick out of the water.

This can slow you down, damage the motor, and make the ride quite loud as the propellers will work harder.

How Long of a Trolling Motor Shaft Do I Need for a Pontoon Boat?

The best trolling motor shaft length for a pontoon boat is 60”. Most pontoons measure between 20’ and 24’. Any pontoon boat that measures 17’ feet or longer typically requires a 60” trolling motor shaft.

The only time you would need a longer shaft for a pontoon boat is if it is longer than 24’. In that case, you can get a trolling motor shaft that is 70” or longer in some cases. Look for pontoon boats with trolling motors that provide between 150 and 175 horsepower.  

The proper length trolling motor shaft paired with the right motor will provide the thrust you need. Pontoon boats need 40 pounds of thrust to power through choppy waters and maintain speed.

Is a Longer Shaft Better on a Trolling Motor?

Longer shafts are better than short trolling motor shafts. You can usually adjust the shaft by pulling it out of the water or lowering it deeper. That said, overly long trolling motor shafts can cause lots of problems.

Trolling motor shafts can drag through the water if they are too long. This makes them harder to tow and it can decrease your speed. Some boaters mistakenly think that maximizing trolling motor shaft length will increase thrust. However, it can have the opposite effect if the shaft is too long.

Trolling motor shafts can also get stuck in mud and debris when riding in shallow water. If the trolling motor shaft length is too long, you can always shorten it. Ideally, you should visit a professional or marine expert to shorten your trolling motor shaft so you don’t damage it.

How Often Do You Need to Replace Trolling Motor Shafts?

You only need to replace trolling motor shafts when they break. In some cases, the shaft can last as long as the trolling motor itself. Trolling motors can last for 10 years or even longer if you take great care of them.

The shafts give out sooner in some cases because they can get tangled, hit the ground, clash with debris, and even get swiped by fish. Ideally, you should check the propellers and motor after each use to make sure they are in good shape. This will ensure that your trolling motor lasts as long as possible.

How Deep Should a Trolling Motor Be in the Water?

Trolling motors should sit at least 12” deep beneath the waterline. The propellers on a trolling motor will create much more noise if the motor is too close to the waterline. Not only can this be annoying when riding around, but it can also ruin your fishing trip.

That’s because the loud propellers will scare the local fish away from your boat, and you won’t be able to catch many fish. Trolling motors must sit even deeper in the water if you are in choppy water with white-capped waves. That’s because your boat will likely bounce up and down.

This makes the motor more likely to be exposed to the air from time to time. Because of that, you must lower your trolling motor 36” deep or deeper to ensure it won’t pop out of the water. A deep trolling motor also ensures that you can maintain a strong thrust even when the water gets choppy.

So, What is the Ideal Trolling Motor Shaft Length?

The ideal trolling motor shaft length is 36” to 60” depending on the boat. Pontoon boats typically need trolling mount shafts that measure 60” because of the distance between the bow and the waterline. Bow mount trolling motors require a 36” to 42” shaft in most cases, and transom mount motors typically need 30” to 36” shafts.