Hi Folks, Probably operator error as are most of my questions. I cruise mostly in Casco Bay and set the range at .5 miles. My GP 1670 or( it says GP 7000 on the face plate), doesn't seem to hold the range, it switches to 100 miles and therefore loses detail. However, more frustrating, all the navigational details go away at any range, channel markers, bouys , etc, it just shows outlines of land forms. I got it to switch back once, however, I don't know what I did. This unit was never integrated with the transducer, I have a separate sounder, (that's another question for later). I've read the instructions thoroughly, and can't figure out if the unit is failing or I'm incompetent. I wind up using Embark on my phone which works great, however tiny display. Thank you very much.