Five short blasts
Signal of doubt. Foundation level, about 2 min. COLREGs Rule 34(d).
The situation
Two power-driven vessels are in sight of one another and closing. The other vessel suddenly sounds a rapid signal. Play it and decide what she is telling you.
What does this signal mean?
- “I doubt that you are taking sufficient action to avoid collision”: At least five short and rapid blasts.
- “I am operating astern propulsion”: Three short blasts.
- “I am in distress and need assistance”: A continuous sounding.
Lookout: Count fast: at least five short, rapid blasts. It is often reinforced at night by at least five short, rapid flashes.
The sound answer
“I doubt that you are taking sufficient action to avoid collision”
Rule 34(d): when vessels in sight of one another approach and either fails to understand the other’s intentions, or doubts the other is taking sufficient action, she immediately sounds at least five short and rapid blasts. Treat it as a demand to act clearly and early.
Why the other options fall short
“I am operating astern propulsion”
Astern propulsion is three short blasts. This signal had at least five, sounded rapidly.
“I am in distress and need assistance”
Distress at sea is signalled by a continuous sounding with any fog-signalling apparatus, among other signals in Annex IV. Five short blasts express doubt, not distress.
Rule 34(d) · Signal of doubt
When vessels in sight of one another are approaching and either fails to understand the intentions or actions of the other, or doubts that sufficient action is being taken to avoid collision, she immediately sounds at least five short and rapid blasts.