We’re coming into the foggiest months of the year right now, and with GPS we are so much safer than we used to be. However, nobody but a madman would navigate in fog on the assured assumption that the instrument can’t fail. In the days of dead reckoning, any buoy looming up was logged for time and distance before the pilot drew another breath. A free fix and a fresh departure! When manna descended from Heaven to the starving Israelites it was not more gratefully received. Even with a GPS Chart Plotter to reassure us, failing to log a buoy in bad visibility might prove a costly mistake. Imagine going below to discover an empty screen, twenty minutes after ignoring a buoy with a name on it!