No they don't expire. They might need updating from time to time, as do electronic charts. The point I was making was that my paper charts will still allow me to navigate perfectly satisfactorily even though they are 14 years old. My Navionics chart, supplied by Chartworld, doesn't even display any more, all because Chartworld don't want to supply me with a small file that would cost them nothing to supply. It's not as if I'm asking them to update the chart, just allow me to use the one I paid so much for originally. I call that miserable customer support.
Contrast that with the support for MacENC - frequent free updates to the latest version, all notified by email to keep us up to date.
Contrast that with the support for MacENC - frequent free updates to the latest version, all notified by email to keep us up to date.