Furuno problems

[sunthief]

My dad has a Furuno 1850 series chart plotter/fish finder. durring inshore fishing trips the fish finder will mark bait as well as fish. However, when we go offshore the screen goes completely red (it's not all bait) weather we are under way or the motors are idle. Any suggestions on how to solve this problem?

[Banshee]

Try taking it out of Auto mode, and adjust the gain down. Also are you in 200HZ or 50Hz. It sounds like a gain issue to me.
JW

[tkoppel]

I agree with Banshee, but to expound. Take it out of auto depth and select a range near but grater than what you are in. Then adjust the gain up and down till you get a good bottom line.