NavList:

David Pike, you wrote:
" Would I be correct in thinking that if you can see the Sun, you can check you are at the North Pole within a mile or two, because you have meridian passage conditions 24/7."

Yes. Equivalent to crossing two Sun lines and ignoring the fact that the pole is "somewhere around here". :) Really, it works the same way it would anywhere on the globe though most navigators would have been confounded by a polar potting sheet, so they created that 'grid navigation' system (no longer necessary, but harmless and popular still). I didn't understand the significance of your comment previously... The missing detail that you not have known: Nautilus did not surface. So no celestial fix. Their only navigation under the ice was their inertial system, and since it was the very first installed in a submarine, repurposed from the inertial system intended for the failed Navaho supersonic cruise missile, I am skeptical of their fix.

Maybe Nautilus was a dozen miles from the pole. Maybe fifty miles from the pole. It was still an extraordinary achievement for the time, and the propaganda value was too important to fuss over exact details. Their distance from the pole was exactly and precisely zero on some line passing through the boat's hull. That's my story, and I'm sticking to it! 

The little brother of Nautilus, USS Skate, also sailed under the ice close to the pole not long after USS Nautilus. Skate returned to the pole and surfaced near it about six months later. 

Frank Reed