Way back when I was in the Navy I was stationed in SC. There I had a boat and fished my butt off. When I would troll at depths of about 150ft and 10 knots SOW I could still see my ball on my sonar. Today, I have a 17ft aluminum with lowrance hook2 splitshot. I can not see my ball on the sonar down 50 feet trolling 2.5 mph SOG. I checked my transducer alignment, sensitivity settings....what am I missing?