I have the 3G version of your radar, an earlier Simrad mult-frequency on an aft pole mount and a Davis Echomaster on the lower spreader...do not have this problem. My reflector is probably 10deg above the radar unit. Perhaps that is why it does not show. Generally these new radars filter out false targets and they disappear from display. Near-in clutter gets filtered when you expand the range. You can also adjust the gain to force a filter. But the great thing about the multifrequency radar is the spectacular close in detail when you want it. I rarely use close in but I don't see the kind of fog they get in Cali.