NavList:

Many years ago, while transporting millions of dollars in gold bullion regularly from South Africa to the US, I fantasized quite regularly on a scenario such as this discussion has brought up. I could handle the navigation problems involved, including arranging deflection of the magnetic and gyro compasses, however, a could never get around the matter of situational awareness of relative azimuth,  both as related to the sun and to the stars, as well as any prevailing sea state, which should alert a competent navigator to any significant alteration of course. Of course, this was long before the electronic navigation of today .