Topic: Image resolution difference between left vs right side

[tracker01]

I am operating an 898c SI. This is within a river system with settings of Range - 90ft, 800kHz, sensitivity - 5, contrast - 10. It seems that it is getting pretty good images to the left while the right side isn't. Travel of boat is mostly center of river trying to keep equal distances to shorelines.   I am looking into what may be causing this and best way to get quality images of the entire river channel. On average the river depth is 7-8ft with some areas of 13-14ft and then 3-4ft within the main channel.  Thanks for any help.

[Gimp]

This is just my uneducated guess and should not be taken too seriously so here goes.

800kHz doesn't shoot straight out to the side very well, but does better at a diagonal. Was the boat tipped at all with more weight to one side of the boat? Does it also show dark to one side in 455kHz? Is there something that might be blocking that side stopping a signal from either leaving or getting back to the transducer? Is there a bunch of air bubbles on the transducer? (that one got me last weekend)

[tracker01]

The transducer was clean of debris, the boat and transducer where level. Didn't think about adjusting the setting while on the water to the 455kHz.

[Humminbird_Greg]

I think that Gimp may have keyed in on most all of the possible causes for this besides the equipment itself.  I would make sure that this happens when travelling in both directions as that will point to or rule out the bottom terrain as a cause as well.
Definitely run the 455kHz at these water depths as it radiates higher into the water column and will get into the shallow water areas much better than the 800kHz will – but that would not cause what you are seeing.
Look for anything that may be blocking the right Si sonar.
Test your unit on someone else’s boat that is running a Humminbird Si model unit and test their unit on your boat.  These do not have to be the same Si models for the test, just be sure to only plug in the power and transducer for the testing.