John, the one tip I would give you is, when using SideVu or DownVu and wanting to make a waypoint of say a boulder, do not simply tap on the boulder and hit mark, it will mark the boat position not the boulder. Make sure to tap the mark at cursor, it is in the upper righthand corner on my unit, a pin symbol with a +. The header on the waypoint screen will say at cursor or at boat.
Just a heads up if you are new to Garmin, I didn’t know this for like a year of owning, however I may not read directions well either!