A recent email exchange with a Mediterranean user drew my attention to a specific aspect of electronic charting : zoom limitation of a chart. ENC vector charts (¹) are classified in 6 categories depending scale : smallest scales less than 1:1.500.000 for global views to largest scale up to 1:4.000 for harbours and anchorages. (²).
In most cases, ENC S-57 (¹) official charts the most detailed have a scale about 1:4000, thus 1 cm on the chart (screen view) represent 40 meters on the ground. With paper chart, the only way to get more details is… to use a a magnifying glass, that provides, as we know, in no case more accuracy. But it is quite otherwise for electronics charts.