pontoon boat trolling motor shaft length

Shaft Length for Pontoon Trolling Motors [Complete Guide]

Cruising on familiar waters makes everything easy and enjoyable especially of a clear summer day. The ultimate and fun fishing expedition is not only determined by the motor’s horsepower but also the precise adjustment of the trolling shaft length.

The shaft length is a vital aspect on every fisherman’s boat and you cannot get it wrong as it will ultimately influence the quantity of your catch. When it comes to choosing a trolling motor, you’ll be surprised how it’s not that difficult.

In this post, we are going to have a detailed and in-depth discussion on how to purchase the ideal trolling motor shaft length for the pontoon boat.

What makes a good pontoon boat trolling motor shaft length?

Water conditions

One of the most vital things that you should always special attention to the water conditions, for those who will be fishing on rivers and lakes that don’t have plenty of waves; then it’s wise to get a short shaft length.

For those fishermen who opt for large water bodies that have turbulent and extreme waves, its always recommended getting a long shaft length that will ensure you have seamless and smooth fishing experience.


Depending on the design and structure of your pontoon boat, some may have sufficient space in front of the bow fencing that provides for mounting or mounting of the trolling motor or stretching a bit.

For other types of pontoon boats, they lack space between the bow on the front edge and the fencing, depending on your boat style you’ll need to make modifications.

For those looking to install a bow mount on their trolling motors (well, it’s quite easy dragging the boar rather than pushing it), it’s always recommend to reshape or cut the front gate on your boat bow.

The change of the design does not entail too much work and can be done in just under an hour. It always wise to be economical and those who want cost-effectiveness when it comes to changing the front gate, you should consider placing the trolling motor at the rear end. It’s a bit lower and you should consider using a low shaft length.


When you are in the market for a trolling motor shaft length for a pontoon boat, an important aspect that you should factor in is the placement of the motor.

Placing the motor on the bow is amongst the most widely used techniques, another viable option though not popular is the placing it at the rear. And lastly, you could also mount your motor on the central motor.

It vital to note, there is no wrong or right way when it comes to placement, but here are some few things that should be put under consideration.

If you decide to place the trolling motor on the bow, you’ll require a long shaft length, the reason being that the bow is always a bit higher when compared to the boat

Shaft length 

Typically, the standard shaft length on the market is 42 inches. To know the exact length of your boat, you’ll first need to measure the distance between the transform to water or where the shaft is mounted.

For the Minn Kota add 20 inches while for the MotorGuide add another 16 inches, choose the nearest measurement. In rough of turbulent waters, a longer shaft is recommended which means the prop will stay 6 inches below the water surface when the boat rolls and pitches.

With little adjustment on the mount, you can always change the vertical position of the motor.


The ratings of trolling motors are measured in pounds of thrust, the general rule of thumb is 72 to 75lb. of thrust will approximately equal 746W of power or one horsepower.

A normal 12Volts motor using 60A will use-up 720W, the power equation is fairly easy: the more the thrust the higher the voltage. Trolling motors come in 36V, 24V, and 12V versions. The maximum thrust of varying voltage ranges between 24V/80lb and 12V/55lb.

The optimal size

When it comes to fishing, the bigger the better. For large boats, they need more power; always consider the current, wind, and wave action when buying a trolling motor. Stronger and powerful motors with a rather longer shaft length run more efficiently at low speeds allowing you to cruise with so much ease.

A 5lb. thrust is always recommended for every 200lb gross weight of the Pontoon trolling boat.

Check out my guide on What Size Trolling Motor For 24-Foot Pontoon Boat?

Bow mount shaft length

The all-important question is what length shaft for a pontoon boat trolling motor be? Choosing the right shaft length together with bow mount motors is vital.

The distance from water-to-bow varies from boat to boat, it’s worth remembering that the bow moves a lot when on the water than on transom. Thus, getting the precise shaft length is imperative.

For a quick calculation, you can begin by measuring the distance from the waterline to the mounting point on your bow. OnOn most occasions, the shaft length should be equal or greater than the resultant sum but not less.

Other factors that should be put into consideration include:

  • For those who fish on rough or turbulent waters, always add an extra 5 inches from the recommended shaft length. This will aid in ensuring the propeller remain submerged regardless of the additional deck being on windy or choppy waters.
  • If you’ll stand up when steering the motor, it’s advised to add 12 inches to required transom length. This ensures it’s comfortable and easier to steer your boat as it brings the motor tiller high up.

How to measure your Bow Mount Shaft Length correctly

what length shaft for a pontoon boat trolling motor
  • For freshwater, the required shaft length should equal 20 inches + Bow to the waterline.
  • For saltwater, the minimum required shaft length should equal 25 inches+ Bow to the waterline.

Transom Mount Shaft Length

The shaft length of the transom mount motor is not essential when compared to bow mount motors. But it doesn’t hurt to counter-check every time you head out.

trolling motor shaft length for pontoon boat

Measurement tips and tricks

Typically, measuring the shaft length of your trolling motor is a simple and straightforward process. However, you should familiarize yourself with a few tricks and tips up your sleeve to get the correct measurement.

While some may find it funny, wait till your prop starts acting up making you lost thrust. Here are a few simple tips to be followed:

  • Always measure in calm waters to get an accurate and exact measurement
  • Factor in the excess weight above the bow, for light boats the bow tends to dip more
  • Try measuring with a full gas tank, gears, etc, to get a rough idea to determine the level of impact when the bow rises. Measuring in real-world conditions will give you the actual look and feel of things.
  • Regardless of the installation placement, you’ll need to also consider the weight of the batteries as well as the motor. A grown man can weight the same as a two 12v batteries and 24v motor
  • Try not going overboard when measuring as it can be quite embarrassing

Final word

If you adhere to every instruction that we’ve laid out above, you will be able to get your preferred results when it comes to the shaft length of your pontoon trolling motors.

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