I've had my 798 for a few months now and it's had a few hiccups, but the update fixed those.
However, the last few times I've been out, the sonar and downimaging depth readings will go bonkers every so often. I might be in 6 ft of water and everything is okay one moment, the next time I look at it, it might read 500 ft and the screens are thin at the top, like I'm really in 500 ft of water. A few minutes later I'll watch the screen expand to the proper depth, as if I went from 500 ft to 6 ft instantly.
I've also noticed the the scrolling stops every now and then.
Any suggestions?