Fly Stim...
I'll have a number 4. Can I get a fried rice and NVG on the side?
Interesting article in this months Practical Boat Owner that basically says sail with out manual nav at your peril. GPS satelites are getting older and their 3 levels of redundancy more or less depleted. Apparently at various times over the last year or so, signals in Scotland have on occasion been up to 40km out and a mile or so out on the south coast. At that was reported by a yacht in harbour!