Our electronic charts in Mexico are not that good. They are based off US Navy mapping from the early 1900's.
As you can see in the photo below Shindig is anchored about 1 mile inland.
Knowing that the charts are crappy we take extra precautions. For example, we'll use the radar during the day and compare the shoreline contour of the chart with the actual contour from the radar.
What we have found is that the charts are off in many places 1/2 to 2 nautical miles.
The Shindig are also GOAL oriented navigators. (Go Outside And Look) - Thanks David from Taj for the acronym