Selecting The Right Size Trolling Motor

Is a bigger trolling motor always the better choice? This article addresses that question and many others to help you choose the right trolling motor for your needs.

Choosing the Right Size Trolling Motor

When selecting a trolling motor, consider the following factors:

Freshwater vs. Saltwater

Shaft Length

Required Thrust

Size

Power Consumption

Note: If you frequently fish in areas with large waves, add 8 inches to your bow-to-waterline measurement.

Bow-Mount Motors

Bow-mounted motors are ideal for anglers who fish primarily in open bow-rider boats or on the fore-deck of bass boats. To prevent damage from grounding, opt for a spring-loaded mount, such as Minn Kota’s BowGuard 360, which allows the motor to swing away upon impact. For very small craft or lightweight sailboats, the trolling motor often serves as an auxiliary engine and is typically mounted on the transom, where it is operated by a tiller.

Transom-Mount Motors 

Transom-mount trolling motors are suitable for anglers who spend more time at the back of the boat or in the cockpit, as well as for sailboat owners who use a trolling motor as an auxiliary propulsion method. These motors come with adjustable brackets that allow for different angles and heights, ensuring the motor’s shaft is submerged to the appropriate depth.

Freshwater vs. Saltwater

Trolling motors designed for saltwater applications are equipped with corrosion protection and enhanced seals on their mechanical and electrical components.

Shaft Length

The standard shaft length is 42 inches. To determine the correct length for your boat, measure the distance from where the shaft mounts on the deck or transom to the water’s surface, then add 16 inches (for MotorGuide) or 20 inches (for Minn Kota). Choose the next closest measurement. If you often fish in rough waters, consider adding an additional 8 inches to your bow-to-waterline measurement when selecting the shaft length. If your measurement falls within overlapping length ranges, opt for the longer shaft. You can fine-tune the motor's vertical position using the adjustment on the mount.

Thrust

Trolling motors are rated by thrust in pounds. As a rule of thumb, 72 to 75 pounds of thrust is roughly equivalent to one horsepower, or 746 watts of electrical power. For example, a typical 12V motor that draws 60 amps consumes approximately 720 watts. The relationship between voltage and thrust is straightforward: higher voltage results in higher thrust. Trolling motors are available in 12V, 12/24V, 24V, and 36V versions, with the most powerful models exceeding 100 pounds of thrust, which is sufficient to move heavy vessels like pontoon boats. Maximum thrust ratings at different voltages are approximately 12V/55 pounds and 24V/80 pounds.

The Right Size 

In general, bigger is better. Larger boats require more power, but it's important to consider wave action, wind, and current when choosing a trolling motor. Choosing a motor with a bit more power can be beneficial; stronger motors tend to run more efficiently at lower speeds and provide a safety cushion when navigating challenging conditions. A good rule of thumb is to allow for 5 pounds of thrust for every 200 pounds of a vessel's gross weight.

Power Consumption

When considering a trolling motor, it's essential to think about your boat's size, the battery capacity you can safely install, and whether you can charge the batteries while on the water. Check the amp draw of the models you’re interested in. For instance, a 24V model with 54 lbs of thrust may only draw 28A, while a 12V model with 44 lbs of thrust can draw 36A. Generally, larger motors require more battery capacity. If you plan to fish from dawn until dusk in a boat that is 16 feet or longer, a 24V motor is advisable. Serious anglers who spend extended time on the water will benefit from a 36V motor.

Advanced Features

Many modern trolling motors come equipped with autopilot and route storage capabilities to help you navigate your most productive fishing routes. With Bluetooth connectivity, you can control these features from your phone or an included remote. Some Minn Kota motors are compatible with Humminbird's MEGA Down Imaging and select fish finders.

Trolling Motor FAQ

How do I maintain my trolling motor to ensure longevity?

Regular maintenance is crucial for ensuring the longevity of your trolling motor. Rinse it with fresh water after use, especially in saltwater environments, and check for debris around the propeller. Lubricate moving parts as recommended by the manufacturer and inspect electrical components for any signs of corrosion or wear.

Can I use a freshwater trolling motor in saltwater?

It is not recommended. Freshwater motors lack the necessary corrosion protection and seals for saltwater use. If you must use a freshwater motor in saltwater, rinse it thoroughly with fresh water after each use to minimize damage. However, it's best to invest in a motor specifically designed for saltwater.

What is the difference between a tiller handle and a foot pedal for controlling a trolling motor?

A tiller handle is a traditional control system that allows you to steer directly by hand. A foot pedal offers hands-free control, enabling you to steer and adjust speed using your feet, which is particularly beneficial for fishing as it keeps your hands free.

Can I use a trolling motor on a kayak or canoe?

Yes, many trolling motors are designed for small watercraft like kayaks and canoes. Make sure that the motor's thrust rating matches the size of your kayak, and choose lighter, more compact models to avoid adding excessive weight.

How do I calculate battery life for my trolling motor?

To estimate battery life, divide the battery’s amp-hour (Ah) rating by the motor's amp draw. For example, if your motor draws 20A and your battery is rated at 100Ah, it will last approximately 5 hours. Running the motor at lower speeds can significantly extend battery life.

Can I use a solar panel to charge my trolling motor’s battery?

Yes, solar panels can be used to charge trolling motor batteries, but their effectiveness depends on the size and output of the panel. For optimal performance, select a high-output panel paired with a charge controller to prevent overcharging the battery.

Can I use a trolling motor in heavy vegetation or weedy areas?

Many trolling motors are designed to handle weedy or shallow areas. However, it’s important to avoid letting weeds entangle the propeller. Some motors come with "weedless" propellers, but you should regularly check the motor for tangled debris to prevent overheating or damage.

Can I retrofit my current boat with a trolling motor if it wasn’t designed for one?

Yes, many boats can be retrofitted with a trolling motor. You'll need to determine where to mount the motor, whether the boat’s electrical system can support it, and if there’s enough space for additional batteries. You might also need to install or adjust the oarlocks or transom mount.