Fish Finder Depth Reading Problems

Fish Finder Guides

If you’re testing the accuracy of your depth finder, your first step should be ensuring the water is deep enough. Shallow water can give inaccurate readings, and testing outside of water can cause damage to your unit.

For best results, test your equipment in a lake, river, or the ocean itself. However, if you’re in deep water and still having trouble reading depth, there are some things you can do.

Fix the transducer Angle

Your transducer uses sonar to determine the depth of the waterbed. This means it sends out a pulse, or a soundwave, that reflects off the bottom of the waterbed and helps your device determine depth.

However, if your transducer isn’t aligned properly, it will send out the pulse of sound at an angle, rather than a direct hit. This can cause a distortion in readings. To fix this, you’ll have to manually adjust the angle of your transducer. The transom-mounted transducer should be parallel to the waterline, as illustrated in the image below.

transducer mounting angle guide

Losing Depth when Moving

There are several reasons that depth reading might be lost or inaccurate lost when you’re moving. It could be because of where you have installed the transducer on your boat, or because of the settings on your device. If your vessel is moving too quickly, it might outrun the return signal from the transducer.

Here are a few troubleshooting steps for transom-mounted transducer

  • The turbulent water near the outboard or inboard/outboard engine can cause the transducer to lose depth. It is important to mount the transom transducer in an area that is free of propeller wash. The image below can help you determine the best location to mount the transducer on the transom. The transducer should be mounted on the starboard side of the boat with undisturbed water flow.
best trasnducer mounting location on the transom
  • If the transducer is installed in the correct position, it is possible that you are losing depth when planing. The best way to solve this issue is to simply set your transducer deeper into the water.

Ensure No Marine Growth on the transducer

An external issue that can affect the accuracy of a fish finder is marine life growing on the transducer. In this scenario, it is important to clean the transducer and apply special paint to the device to prevent future issues.

Transducers can be clean using soap or detergent with water. Alternatively, you can use sandpaper to remove any marine growth. Lightly sand the device to prevent any exterior damage. Once cleaned, you can apply a coat of antifouling paint to help protect the transducer from further marine life growth.

Check the transducer Settings in Fish finder

Your issues might be as simple as having the wrong transducer type selected in your settings. Be sure you go through your menu to ensure you have the correct transducer selected to ensure an accurate reading.

Modern fish finders come with a bevy of features and settings. While these are incredibly useful for anglers, they can also cause issues if incorrectly changed. Some settings that need attention include:

  • Ensure the transducer type setting is correct. If it displays something other than the currently attached transducer, switch to the correct transducer from the list.
  • Most fish finders come with both a freshwater and saltwater mode. Analyze this setting and ensure you’ve turned it to the appropriate type for the current situation.
  • Under the sonar menu, make sure you’ve turned on sonar and the mode is set correctly. Set the sonar mode to down when using transducers with multiple beams. When the transducer is a wide side device, use the setting labeled “side.”

Inspect the Transducer Connections

An impressive electrical device like a transducer has a lot of connection points that could cause issues. Check the battery terminal, fuse, fuse holder, depth sounder connectors, and the transducer connector for any corrosion or an improper connection.

In the event of any corrosion, you can clean it off using an abrasive element like sandpaper mixed with water and baking soda. 

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