What action should be taken when a boater encounters heavy fog?

When a boater encounters heavy fog, the safest action is to reduce speed and use sound signals. Reducing speed is crucial because visibility is limited in foggy conditions, and navigating at a slower pace allows better reaction time to potential hazards, such as other boats or obstacles that may not be visible until very close.

Using sound signals, such as a foghorn, helps communicate the boat's presence to others nearby. In fog, other vessels may not see you approach, but they can hear your sound signals, which enhances safety for everyone on the water. This practice is aligned with the navigation rules that require vessels to signal their presence under conditions of reduced visibility.

The other options may seem tempting but could lead to dangerous situations. Speeding up to exit the fog quickly could significantly increase the risk of collision, as the boater would have less time to react to sudden obstacles or other vessels. Stopping and turning off sound devices would prevent any warning to nearby vessels, increasing the risk of accidents. Anchoring in place, while providing safety from movement, could also pose a danger if other vessels are unaware of the anchored boat's position, as they may collide with it, especially in heavy fog where visibility is severely impaired.