Whether you're chasing bass on a lake or working the flats for redfish, a trolling motor is one of the most productivity-defining pieces of gear on your boat. But with dozens of options across thrust ratings, shaft lengths, voltage systems, and GPS anchor features, knowing how to choose one isn't obvious. This guide covers everything you need to make the right call.
Step 1: Match Thrust to Your Boat
Trolling motor thrust is measured in pounds (lbs). The general rule of thumb is 2 lbs of thrust per 100 lbs of loaded boat weight (including gear, fuel, passengers, and the boat itself). In practice, most experienced anglers recommend sizing up by 10–20% to account for wind, current, and wave resistance.
- Boats under 2,000 lbs: 55 lbs thrust
- Boats 2,000–3,000 lbs: 80 lbs thrust
- Boats 3,000–4,000 lbs: 101–112 lbs thrust
- Larger vessels: Consider 24V or 36V systems with higher thrust ratings
Step 2: Choose Your Voltage System
Trolling motors run on 12V, 24V, or 36V systems.
- 12V — One battery. Simple, lighter, and adequate for smaller boats and moderate use. Max thrust typically tops out around 55 lbs on 12V.
- 24V — Two batteries wired in series. More power and longer run time. Covers most bass boats and medium center consoles.
- 36V — Three batteries. Maximum power and endurance for larger boats, heavy loads, or all-day fishing in tough conditions.
Step 3: Calculate Shaft Length
The motor head needs to stay submerged during operation, especially in rough water. The standard formula is: measure from the mounting point to the waterline, then add 18–20 inches. Bow-mount motors on boats with high freeboard commonly require 52" or 60" shafts. Transom mounts on jon boats may work fine at 36".
Step 4: Bow Mount vs. Transom Mount
- Bow mount — Pulls the boat forward. Provides more precise boat control and is the standard choice for tournament and serious recreational fishing. Typically features foot pedal or wireless remote steering.
- Transom mount — Pushes the boat forward. Simpler, lower cost, and easier to move between boats. Common on kayaks, jon boats, and smaller aluminum fishing boats.
Step 5: GPS Anchor and Spot-Lock Features
Modern trolling motors with integrated GPS can hold your exact position using spot-lock (GPS anchor) technology — even in wind and current. This eliminates the need for a physical anchor in many situations and keeps your bait in the strike zone while you focus on fishing.
The Garmin Force trolling motor integrates directly with Garmin chartplotters, allowing you to control the motor, set waypoints, and use AutoPilot heading hold from your MFD touchscreen — without a separate foot pedal or handheld remote. It's a premium option designed specifically for anglers who are already invested in the Garmin ecosystem.
Freshwater vs. Saltwater
For saltwater use, choose a motor specifically rated for saltwater with sealed components, anodized or sealed propeller hubs, and corrosion-resistant hardware. Rinse your motor with fresh water after every saltwater use regardless of rating.
Browse the full trolling motor selection at Egret Marine and find the right setup for your fishing style.