Or alternatively, and in addition to your very fine chart plotter, you could carry appropriately scaled official paper charts of the area in which you are Sailing. Keep in mind that the electronic charts you are using in your chart plotter may not be of the standard required by SOLAS and IMO, but at best they cannot show more detail than is included on an official paper chart because it is that detail on the paper chart that has been digitised to make up your electronic chart. Also, when using your electronic chart display, you should change ranges at short and regular intervals, and move the mapped area across the screen in order to look ahead so that detail not shown on larger ranges but which is included in the shorter ranges does not go undetected. If you have the appropriate official paper chart onboard, all of the detail will be on it, so the answer would be to take a look at it periodically to ensure you have not missed anything.
Was that course you took held by one of the firms who make chart plotters, and was the instructor someone with an interest in selling as many plotters as possible?? And did you ask him if the charts in use on that plotter were officially recognised as being of a standard approved in accordance with SOLAS, because it’s highly likely that they were not. That doesn’t mean to say that they were entirely unsafe to use, but on start up of the chart plotter you are reminded that the display is only an aid to navigation and that it does not replace the need to carry paper charts !!
There’s nothing wrong with having two chart plotters onboard, as much as anything one could fail and leave you with just your paper charts. If that happened you’d need to resurrect those rusty navigation skills that people of my age used before the days of GPS and chart plotters. Those skills got us around the world, including the Juan de Fuca straits on our way to Vancouver, New Westminster, Victoria and other ports in that area both in Canada and the USA, and without mishap other than to upset the “the Old Man” one morning while he was having breakfast and I phoned down to him to report that I had a position after three days of bad weather when we had seen nothing but rain and mist, and which now put us about 100 miles ahead of where we thought we were (thanks to the Kuroshio current).