If your vessel is underway in fog and you hear one prolonged and three short blasts, what does this indicate?

If your vessel is underway in fog and you hear one prolonged and three short blasts, what does this indicate?

• A. A vessel being towed
• B. A vessel under sail
• C. A vessel anchored
• D. A vessel not under command

Answer: (A)

In fog, sound signals tell other vessels what your vessel is doing or its status. One prolonged blast followed by three short blasts is the standard signal that a vessel is being towed. Recognizing this helps you understand that the towed vessel and its towing arrangement may have limited maneuverability, so you should take early, well-judged action to give them plenty of room. Other conditions—like not under command, anchored, or under sail—use different signals, so hearing this exact pattern points specifically to a towing situation.

In fog, sound signals tell other vessels what your vessel is doing or its status. One prolonged blast followed by three short blasts is the standard signal that a vessel is being towed. Recognizing this helps you understand that the towed vessel and its towing arrangement may have limited maneuverability, so you should take early, well-judged action to give them plenty of room. Other conditions—like not under command, anchored, or under sail—use different signals, so hearing this exact pattern points specifically to a towing situation.