Under both International and Inland Rules, fog signals for vessels underway must be sounded at intervals of not more than how many minutes?

Under both International and Inland Rules, fog signals for vessels underway must be sounded at intervals of not more than how many minutes?

• A. Not more than two minutes
• B. Not more than four minutes
• C. Not more than one minute
• D. Not more than three minutes

Answer: (A)

In fog or restricted visibility, vessels must announce their presence to others by sounding a fog signal at regular short intervals. The standard interval for vessels underway is not more than two minutes. This keeps other mariners aware of your location and movements and provides a timely cue for collision avoidance. This rule is mirrored in both the International Regulations and the Inland Rules, so the same two-minute maximum applies regardless of which regime you’re operating under. The two-minute limit strikes a balance: it’s frequent enough to be reliable in varying conditions, but not so often that it becomes excessive or distracting. The other interval options would either be too long to ensure consistent warning or incorrectly imply a more aggressive signaling pattern. Not more than two minutes is the specific requirement you’ll apply in restricted visibility when you’re underway.

In fog or restricted visibility, vessels must announce their presence to others by sounding a fog signal at regular short intervals. The standard interval for vessels underway is not more than two minutes. This keeps other mariners aware of your location and movements and provides a timely cue for collision avoidance.

This rule is mirrored in both the International Regulations and the Inland Rules, so the same two-minute maximum applies regardless of which regime you’re operating under. The two-minute limit strikes a balance: it’s frequent enough to be reliable in varying conditions, but not so often that it becomes excessive or distracting.

The other interval options would either be too long to ensure consistent warning or incorrectly imply a more aggressive signaling pattern. Not more than two minutes is the specific requirement you’ll apply in restricted visibility when you’re underway.