The day that my
GPS position jumped 11 miles probably due to local military activity was cloudy. I don't know how a
sextant would have helped that day. If I had been threading my way through a narrow channel or some
reefs the
GPS error might have been an issue, but 11 miles was still closer to my actual position than I could have determined with a
sextant on a cloudy day. Can any of the sextant experts tell me how to use a sextant to thread my way through a narrow winding channel? What's my backup for the sextant on cloudy days?
I don't worry about these things because I Know where I am, I know where I'm going, I know how I'm going to get there and I know roughly what external influences are affecting my
boat. I'm confident that given a functional
compass, I'm going to get pretty close to where I want to be even on a cloudy day. The GPS just helps make it a little easier. If the GPS suddenly jumps 10 miles or even a hundred, I'm not going to believe that I was magically teleported across the planet, I'll simply ignore it until it makes sense with what I know. If you have so little situational awareness that a GPS failure is a major crisis, perhaps you should take up another lifestyle.