How well are your waters marked?

After reading quite a few threads on bent shafts and ripped up props, I wonder how well the water is marked. Ours is pretty good, as long as the water level remains at or near full pond. In the summer, it can drop as much as 8 feet and then, obviously, areas that weren't risky before, become outdrive eaters. I still find comfort in knowing the lake well and paying attention to the chart.