I recently mounted a 596 hd di on my boat. everything seems to be working alright but when I get to probably 7 or 8 mph I start getting vertical lines on the chart. this happens both on 2d and di. I followed all the mounting instructions and think I have it in the best possible place on the transom. any input or advice would be great on how to fix this or just any tips on this unit and its use. Im very new to this unit so any pointers will help. Thanks!
