Chances are when you are on the water you will occasionally encounter fog, making navigation a challenge. Because of the time it can take to stop or turn a marine vessel, fog is usually considered dense for mariners if it reduces visibility to less than 1 mile. Fog can form quickly and catch boaters off guard. Visibility can be reduced to a few feet, which can disorient even the most experienced boaters. The international standards for describing reduced visibility in marine forecasts are as follows:
- Very Poor: Less than 0.5 nautical miles
- Poor: 0.5 to less than 2 nautical miles
- Moderate: 2 to 5 nautical miles
- Good: Greater than 5 nautical miles
Learning to navigate through fog (or avoiding it) is critical to safe boating. These safety tips will help to keep you safe:
- Slow down to avoid collisions.
- Turn on all of your running lights, even in daytime.
- Listen for sounds of other boats that may be near you or for fog horns and bells from nearby buoys.
- VHF NOAA Weather Radio should broadcast important information concerning the formation, movement or dissipation of the fog. Pay close attention.
- If your vessel has radar, use it to help locate dangers that may be around you.
- Use GPS or a navigation chart to help obtain a fix on your location.
- If you are unable to get your bearings, stay put until the fog lifts but make sure you are in a safe location.
- Be familiar with horn and bell sounds you should produce to warn others around you when in dense fog.
- Have a compass available. Even if you don't know where you are in the fog, with a compass you can determine the direction you are navigating.