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No Bottom

Lowrance Chartplotter

Severity: Moderate

Source: OnlyErrorCodes.com — Every error code. One place.

Lowrance HDS Sonar 'No Bottom' Reading — Transducer Fix

What Does This Error Mean?

'No Bottom' on Lowrance sonar means the transducer is connected but isn't returning a usable bottom return.
Most often caused by transducer turbulence at speed, marine growth on the face, an air bubble under a transom mount, or wrong transducer type setting.
Slow down, clean the face, check for trapped air, and confirm transducer type in settings.

Affected Models

  • Lowrance HDS Live
  • Lowrance HDS Carbon
  • Lowrance HDS Pro
  • Lowrance Elite FS
  • Lowrance Hook Reveal

Common Causes

  • Boat moving too fast — transducer hit aerated water
  • Marine growth on the transducer face
  • Air pocket trapped under the transducer mount
  • Wrong transducer type set in chartplotter settings
  • Transducer cable kinked or pinched

How to Fix It

  1. Slow down and watch for return.

    If the bottom comes back at idle, the issue is transducer turbulence at speed.
    The fix is repositioning — your transducer is in disturbed water from the hull or another fitting.

  2. Inspect the transducer face.

    Lift the boat or dive the hull (if water is calm and you're trained).
    Look for marine growth — slime, barnacles, weed.
    A bristle brush and warm soapy water clears most growth.

  3. Check for trapped air (transom-mount only).

    If the transducer was installed with the bottom edge above the water line, air can pool against the face.
    Adjust the bracket so the face sits 1/4 to 1/2 inch below the hull bottom.
    The face must be fully submerged at idle.

  4. Confirm transducer type setting.

    On the chartplotter: Settings → Sonar → Transducer.
    The selected type must match what's actually plugged in — Active Imaging 3-in-1, HDI, B260, etc.
    Wrong type = wrong frequency = no return.

  5. Test the cable.

    Trace the transducer cable from the unit to the transducer.
    Look for kinks, pinches, or damage where it enters the bilge.
    Wiggle the connector at the chartplotter while watching sonar — flicker means a bad connection.

  6. Try a sonar reset.

    Settings → Sonar → Reset Sonar to defaults.
    Set the transducer type back, run again.

Frequently Asked Questions

Can I run sonar at high speed?

Some transducers are rated for high-speed operation — most thru-hulls are.
Transom mounts vary.
Read your transducer's spec sheet for max speed rating.
Beyond that speed, expect aerated returns.