This section of a vector plotter chart contains two navigation buoys. Neither shows any significant detail about how it is lit. The only way to find out is either to zoom in, which may or may not give you the answer, or to interrogate the chart by asking it for ‘info’ via the cursor. This particular chart will then deliver all you may wish to know. It’s not ideal, but at least the data are there. Some vector charts, however, simply don’t have the information. It’s vital to appreciate where you stand, so take a long critical look at your electronic chart kit before it really matters. If it falls short in this way, carrying full paper backup is even more important than usual. You know where you are with paper.