The GPS position
 

While surfaced, you are always able to see your position on the map. This is very unrealistic. GPS wasn’t even imagined at the time.

It obviously helps a lot, especially when playing solo. But it also reduces the importance of having a Navigator.

It makes no sense to have the exact position, as the only point of reference when surfaced is the stars, which gives you an approximate position comparable to knowing which zone you start in.

Normally, your absolute position on the map doesn’t matter. The important thing is your relative position to where you were before, eg. when you checked a bearing the last time.

Also, as long as we have GPS position there is no point in using the echo sounder as the depths seems to be plotted on the chart.

Finally, if they add coastal zones where absolute position actually matters, the positon should definitely be determined by the Navigator and not the GPS.

A toggle when starting the game “GPS on/off” would be a great addition to the game.

GPS Position Thoughts
 

It's not a "GPS" position in my opinion. It's a representation of your position
which is kept up to date by the simulation/navigator.
If we had to play with star charts and a sextant it would be a navigation simulator rather than a submarine simulator.
I agree it would be fun to have such an option available, however, it's not really the point of this particular simulation.