Garmin maps are pretty dang good on the river stuff. Limestone bay is decent. Mouth of flint is good. But back towards Big A, it’s not mapped by Garmin. One thing I do like is you can highlight different depth ranges different colors. That is custom. You can make it highlight any range you want. Jump in the boat with me this weekend I’ll give you full access to the unit. Mess with it see if you like it. Mine is the 93sv UHD.