Which signal is used when you do not understand an approaching vessel’s course or intentions during daylight?

Which signal is used when you do not understand an approaching vessel’s course or intentions during daylight?

• A. Not less than five short blasts
• B. Five long blasts
• C. One prolonged blast
• D. Two short blasts

Answer: (A)

Not less than five short blasts is the standard signal used when you do not understand another vessel’s course or intentions. In collision avoidance practice, this sound pattern communicates doubt or ambiguity about what the other vessel plans to do, prompting them to clarify or change course to reduce risk. The daylight condition doesn’t change the meaning—the signal is about understanding, not visibility. Other signals have different purposes, such as indicating a maneuver or warning; they don’t express uncertainty about the other vessel’s intentions in the same way.

Not less than five short blasts is the standard signal used when you do not understand another vessel’s course or intentions. In collision avoidance practice, this sound pattern communicates doubt or ambiguity about what the other vessel plans to do, prompting them to clarify or change course to reduce risk. The daylight condition doesn’t change the meaning—the signal is about understanding, not visibility. Other signals have different purposes, such as indicating a maneuver or warning; they don’t express uncertainty about the other vessel’s intentions in the same way.