A chart plotter is a double edged sword. I think overall their is benefit in the BVI to having them onboard. They are simply one tool in your navigation tool box. Over reliance on the plotter can lead to issues. Cruising guides and charts need to be in use also. Chart plotters are a funny thing. The GPS position will normally be exact. The chart itself that the position is over layed on by the plotter is where problems show up. The entrance to Anegada is a well known example. The main entrance to the North Sound is interesting because depending on which direction you are entering from it will show a different position because it is overlaying different charts depending on where the boat is coming from. One chart is correct the other a ¼ mile off.
G