We recently purchased a boat with a Garmin 498 GPSMap Sounder on it. The specs call for it to have a range of around 1500ft. However, I can't get the sounder to register much over 100ft. I know their is a depth range setting so the screen stays in a certain depth range but the depth reading basically quits working after it exceeds 100ft. Does anyone have any ideas why this is?
Also, the sounder doesn't work at all at speed. I'm guessing the transducer needs to be lowered so its catching clean water at speed. Is this correct?