How to deal with bad weather such as fog at sea?

When there is fog, snow, storm or haze on the sea surface, and the visibility at sea is less than 2 nautical miles, the commonly used lights or other visual signals will lose their function, and navigation is usually carried out by sound. There are many sounding devices for navigation, such as fog whistle, fog bell, fog whistle and fog horn. The "Fog Bull" used in Qingdao, China is only an acoustic navigation.