How to Choose the Right Shaft Length for Your Garmin Trolling Motor

How to Choose the Right Shaft Length for Your Garmin Trolling Motor

Shaft length is one of the most overlooked specs when buying a trolling motor — and one of the most important. Get it wrong and you'll lose thrust efficiency, suffer prop cavitation in chop, and undermine your GPS anchor performance. Get it right and your Garmin motor will perform exactly as designed.

Here's how to choose the correct shaft length for your boat and fishing conditions.

Why Shaft Length Matters

The prop needs to stay submerged at all times — especially in rough water. If the shaft is too short:

  • The prop breaks the surface in waves, losing thrust
  • GPS anchor hold becomes inconsistent
  • Motor works harder, draining your battery faster
  • Steering response degrades in current or wind

A shaft that's too long isn't ideal either — it adds unnecessary drag and can complicate stowing on smaller boats.

General Shaft Length Guidelines

Shaft Length Best For
48" Small freshwater boats, calm water, low bow height
63" Bass boats, moderate chop, mid-range bow height
75" Bay boats, offshore, higher bow height
90" Large offshore hulls, heavy chop, tall bow
110" Extreme offshore conditions, very tall bow, big water

Rule of thumb: Measure from your bow mount to the waterline, then add 18–20 inches. That's your minimum shaft length.

Shop Garmin Force Kraken by Shaft Length

The Garmin Force Kraken is available in five shaft lengths to match any boat and condition:

Saltwater vs Freshwater Shaft Considerations

If you fish saltwater, shaft length selection becomes even more critical. Offshore conditions — wind, current, and wave action — demand longer shafts to keep the prop submerged and maintain GPS anchor hold. The 75" and longer Kraken models are the preferred choice for bay and offshore applications.

For freshwater and calm inshore use, the Garmin Force Current Kayak Motor or a 48"–63" Kraken will cover most scenarios.

Common Shaft Length Mistakes

  • Measuring bow height wrong: Always measure with the boat loaded and in the water, not on a trailer.
  • Going too short for offshore: The most common mistake for saltwater anglers upgrading from freshwater setups.
  • Ignoring wave height: If you regularly fish in 2–3 ft chop, size up one shaft length from your baseline measurement.

Still Not Sure?

Contact us at Captain Mason Yacht Services and we'll help you match the right Garmin motor and shaft length to your specific boat and fishing conditions. You can also browse our full Garmin Trolling Motors collection for a complete look at all Force Kraken options.

Related Guides

Back to blog