Using Instruments in Fog

Without visual references, you must rely on instruments. GPS provides your position — plot it on the chart regularly. The echo sounder gives depth — compare it with the chart to confirm you are where you think you are. Following a depth contour can guide you along a safe route.

Radar, if fitted, can detect other vessels, land, and large buoys. AIS shows other vessels with transponders. Even without these, a handheld GPS and a depth sounder are invaluable. Keep your compass lit and visible.