One of my goals next year is learning more on how to use my fishfinders to help find fish. Here’s an issue I have- I have 2 garmin UHD’s networked together. When I’m idling a bank I see fish and structure, but once I stop and start fishing I don’t see 1/4 of it on the front unit. Is it that big of a difference in 3mph vs .3mph, or something off?,