I have purchased a garmin depth finder,gps unit. It seems to lose
bottom above 9 knots in salt water. This is installed on a 16'
carolina skiff. Before this unit i had an eagle depth finder and it
did the same way. I though maybe it was a bad unit so i bought this new
and undated unit and it seems to do the same way. I have been told it
is because it is on a flat bottom boat but i have to belive there is a
way to mount it so this does not happen. Maybe i need to adjust the
height but it is installed as per the mfg. instructions. It is a
transom mount. Any advise would be very helpful.

Thanks,
Sidney