Need some shallow & weedy sonar depth sounding advice

[Dr Cube]

I have to travel through an extremely weedy and shallow area and down a river to get to a maintenance marina. The other day I ventured to the region to scope things out and the sonar started giving false depth readings that were incorrect (too shallow) according to the charts. This freaked me out because I don't want to rely on charts alone to get to my destination.

When I looked at the sonar screen it was total garbage. Are there any settings I can change to improve depth accuracy among heavy weeds? The water depth where we are is generally below 50 feet.

I have a 2024 R27OB w/ the 8612xsv chartplotter. I don't know which transducer we have, and Garmin's manual says what's possible depends on the transducer.

 

[fishheadbarandgrill]

You'll want to make sure you're on the high freq setting for the sonar. You can set that on your chart plotter. It will probably be 200 Khz. I often go in and manually set the gain and depth range when I'm in really shallow water (less than 6') and select sonar for the display so I can get the full picture of the bottom and make adjustments as needed. You'll find that all you'll need to adjust is the gain once you set your depth range and freq. I have a 2011 era GPSMap 5215 but I'm betting you'll have the same type setting for your sonar through your chart plotter. There may be other proprietary settings based on your transducer, again, set through the sonar settings on your chart plotter. You can also call your local Sea Tow or BOATUS and see if they have any local knowledge on the depths for your track.