In the last chapter I looked at whether or not it was safe and seamanlike for us offshore sailors to completely dispense with paper charts for our primary navigation system, and I concluded that it was. An opinion that was agreed with by most of the people who commented, albeit with some cogent reservations that are well worth reading.
Now I’m going to look at the thorny issue of backup and redundancy and more specifically backup without paper charts. Is that even possible, or must we continue to carry at least some paper charts in case the electronics bite the big one? And if it is possible to dispense with paper completely, what combination of electronic gear and electronic charts would constitute a proper and seamanlike backup?