Speed is Missing or Incorrect

No Water Speed Displayed

Before attempting the steps below, power on your depth sounder without enabling any special options or custom settings. This helps determine whether the issue is related to configuration rather than hardware.

1. Set all features to Auto, or select Restore Defaults from the Setup menu.
2. If possible, test your depth sounder on a friend’s boat that:
   • Uses the same model depth sounder
   • Has a compatible speed gauge installed

This comparison helps identify whether the issue is with the depth sounder itself or with accessories, cabling, or installation.

• If the issue occurs on both boats, return the depth sounder with a detailed description of the problem.
• If the depth sounder works correctly on your friend’s boat, continue with the checks below.

Additional Checks

• Verify that your depth sounder supports boat speed readings. Refer to your Operations Manual.
• Confirm that all required accessories (such as the speed gauge/paddlewheel) are properly connected. Refer to your Operations Manual.
• Some depth sounders can be configured to hide speed data, even when the speed gauge is functioning. Check your settings and adjust them as outlined in the Operations Manual.
• Inspect the paddlewheel for weeds, debris, or obstructions.
  • After clearing obstructions, spin the paddlewheel by hand.
    • If a speed reading appears, the issue is resolved or related to paddlewheel mounting.
    • If the paddlewheel does not spin freely, the shaft may be bent or the bushings may be worn.
• Replacement parts may be available through Humminbird Customer Service, or the entire paddlewheel assembly may need to be replaced.

Incorrect Speed Reading

Boat speed readings from your depth sounder may differ from:

• Your boat’s analog speedometer
• Speed readings derived from GPS

Why Speed Readings Differ

• Boat speedometers typically measure speed using water pressure (via a submerged arm or pressure tube). These components can become clogged, bent, or fatigued, resulting in inaccurate readings.
• GPS speed is calculated using distance over time (speed over ground). Wind, current, and heading can cause GPS speed to differ from speed through the water.
• Your depth sounder measures speed through the water using the paddlewheel, which is independent of GPS path or steering accuracy.

Installation Considerations

Proper installation of the speed gauge is critical for accurate readings.

• The paddlewheel requires a steady flow of clean, non-turbulent water, similar to a transducer.
• Due to hull design, some boats cannot provide accurate paddlewheel speed readings regardless of installation quality.

Installation Guidelines

• The bottom of the speed gauge should be flush with the bottom of the hull.
• Paddlewheel support arms should:
  • Run parallel to the hull
  • Appear as an extension of the hull when viewed from the side
• If needed, use an angled mounting wedge to achieve proper alignment.
• Ensure the paddlewheel is oriented straight toward the bow. Angled installation will produce inaccurate readings.
• Avoid mounting the speed gauge:
  • Behind or too close to other hull components
  • In areas where cavitation or turbulence may occur
• At high speeds, the paddlewheel may lift out of the water, which will cause incorrect readings.

Additional Checks

• Clear any weeds or debris from the paddlewheel.
• If the paddlewheel does not spin freely:
  • The shaft may be bent
  • The bushings may be worn
  • Replacement parts or a new speed gauge may be required
• Confirm the depth sounder is set to the correct speed units:
  • MPH (Miles Per Hour)
  • KTS (Knots)
  • KPH (Kilometers Per Hour)

Refer to your Operations Manual for instructions on changing speed units.

Note: Not all depth sounders support all speed unit options. Verify unit capability in your Operations Manual.

Still Having Issues?

If the problem persists after completing all steps above, please contact Humminbird Customer Service for further assistance.