BL, I was not drawing any inference on modern systems simply that you need to know the relative location of one buoy to the next.
Jumping further back in past, at Jutland the relative position of the ship's could not be determine with complete accuracy as there was no time synchronization.
Today there are many means to determine relative positioning because it is essential, not a weaknesses as was the case with the older systems - note: I never mentioned the N-word.