A sailboat is underway in the fog. What sound signal should you hear?
Some sailors say that a foghorn is needed, while others insist on an air horn. The answer may depend on what type of waterway one sails and the distance to shore or other boats. For example, nearshore waters will require a shorter range warning than deep-sea areas where ships can run aground without notice.
There are advantages to both types of signals and disadvantages. A foghorn can warn sailors up to 20 miles away, while an air horn cannot be heard more than two miles away.
Foghorns have a lower intensity (volume) so they don’t disturb other boats but may not be as loud enough for some people who might need hearing assistance or live on the shoreline where there is no natural noise from waves crashing against it.
Air horns typically provide a higher-intensity sound that is easier to hear at greater distances than foghorns; however, many find them too harsh because they’re louder and repetitive over long periods of time, especially if there’s any wind blowing across the water into the land.