When your transducer is out of the water, the fish finder may display any value from zero to its maximum depth range, or the depth reading may continually change. These readings are not meaningful because there are no true bottom returns for the sonar to detect.
Testing depth performance with the transducer out of the water is not recommended.
Jump To:
- Why Does the Depth Reading Change Out of the Water?
- Is an Out-of-Water Depth Reading Accurate?
- How Should I Test My Depth Reading?
Why Does the Depth Reading Change Out of the Water?
All electronic devices produce some amount of electrical noise. While the transducer is operating normally in the water, actual sonar returns are much stronger than this noise, allowing the fish finder to identify the bottom and provide a depth reading.
When the transducer is out of the water and the fish finder is operating in Normal Mode, the unit continues searching for the bottom. Because there is no true bottom return, the fish finder may interpret small noise signals as sonar returns and display them as depth.
This is why one fish finder might display 0 feet, another could display 1 foot or 1,100 feet and another may continuously change between different depths.
Is an Out-of-Water Depth Reading Accurate?
No. A digital depth reading displayed while the transducer is out of the water has no meaningful significance.
If the displayed depth happens to appear correct, it is coincidental and should not be used to evaluate sonar or depth performance.
How Should I Test My Depth Reading?
For a meaningful depth reading, evaluate the sonar with the transducer operating in water where it can receive actual sonar returns from the bottom.
Do not use an out-of-water digital depth reading to determine whether the fish finder or transducer is working correctly.
