First of all: this is NOT a debate about the merits of keeping c-nav around in the 21st century. I’m pro-c-nav and nothing is going to change my mind. What I do want to talk about is a specific problem with using c-nav as a backup. We all know that c-nav is still around because everyone’s GPS unit craps out once in a while, and there’s still a chance that one day some idiot is going to shoot a satellite down and we’re all going to romping around out there like chickens with our heads cut off. I agree with this line of reasoning and continue to support c-nav because of it.
So here’s the problem: whenever we do c-nav on a ship these days we get our accurate time to do it with FROM THE GPS UNIT. So when the GPS goes down how are we going to do c-nav? I know some ships have carriage requirements for sextants, nautical almanacs, 229 tables, etc… but is there a carriage requirement for marine chronometers? Obviously we need some kind of accurate time keeper but what would the average ship do for accurate time keeping ability without a GPS?
Where’s John Harrison when you need him?