On the contrary. The navigation specialty makes it a point to know how to navigate using stellar observations as a standalone entity, because at sea, there is always a possibility that electronic equipment fails in salt air, since it can corrode the electronics inside.
The most basic starting point of any navigational study, is the fact that the North and South Poles are oriented to specific spots in the sky at all times, and that they are only visible from the respective hemispheres of the globe at night.
These two points, do not require outside information to calculate the position of the North Star, nor the "Southern Cross " pivotal point. They remain in the same position with the rest of the sky rotating around them. They are a constant.
The angular difference from the horizon to the North Star (or the pivotal point of the southern cross) corresponds to the latitude you are at at the moment of observation.
You can use a simple protractor, soda straw, a piece of string, and a flat washer to make the observation, and calculate for yourself.
Tie the washer to one end of the string. Tape it to the middle of the flat edge of the protractor.
Tape the soda straw to the flat edge of the protractor lengthwise.
Site the North Star (the first star of the Little dipper's handle) then pinch the string to the protractor along the curved side to see what it reads.
Since you cannot measure from the horizon with this device, it measures backwards from a point directly beneath you (also known as the zenith angle) Use the number that is less than 90, so you can accurately figure things out (as far as you can with such a simple device). Take the measurement, and subtract it from 90. this is your angular distance from the horizon.
You will find that it correponds to the latitude you are at.
Now, if you are in the southern hemisphere, site the Southern Cross pivotal point, and use the exact same method used above to come up with you reading. Place a negative sign on the number, and it is your southern latitude.
This should lead to the conclusion that the Universe or celestial star map has two pivotal points in the sky. According to the Flat Earth Hypothesis this is not a possibility.
Again, I ask how is this possible?