I've been searching around to find a decent fish finder/ depth finder for around $100. I have a 15ft high tide that I plan on fishing in creeks as well as the inlet. The main purpose I need it for is to look for holes up in the creeks or some rock piles just off the beach. No more then 50ft of water but mostly between 3ft-30ft. I was looking at the lowrance x4 pro as well as the Garmin 140 but both seem out of date. Any recommendations of a better one or a review of one of those two?