Precautions 2

Other steps to be taken in restricted visibility are:
Post a lookout for lights and signals of other vessels well forward, away from the noise of the engine.
If the boat is fitted with radar, turn it on as soon as the visibility is reduced, and place a crew member with radar experience to monitor it.
If the engine is not running, then start and warm it up to ensure that it will start instantly in case of emergency.
If you have a GPS use the data and plot an accurate fix on the chart.
However, always check this data against other sources, such as radar, Loran or depth recorder.
You may have to reduce your speed, but always keep steerageway on your boat.