While underway in fog, you hear the fog signal of another vessel ahead. If a risk of collision exists, you must __________.

In situations where you hear the fog signal of another vessel while underway in fog, it is crucial to prioritize safety and navigation. The correct action is to slow down to bare steerageway and navigate with caution. This approach allows you to maintain control of your vessel while reducing the risk of collision.

By slowing down, you can better assess the situation around you, giving you time to react appropriately to any potential hazards. Maintaining bare steerageway means you can still maneuver if needed, while navigating with caution allows you to be aware of your surroundings. This is particularly important in foggy conditions where visibility is reduced, and other vessels might be challenging to see.

Maintaining your course and speed or increasing speed to pass through the fog more quickly could lead to dangerous situations, as you may not have time to respond to another vessel that suddenly appears. Continuously sounding your horn does not contribute to collision avoidance and doesn’t help in determining the direction or speed of nearby vessels.

Overall, this approach aligns with the Rules of the Road, which emphasize the importance of being able to take action to avoid collisions, especially in restricted visibility scenarios.