🔍 Key Concepts

• Narrow channel sound signals (International Rules) used when overtaking another vessel • Difference between signals used for maneuvering in open waters (port/starboard turns) and narrow channel overtaking signals • Which vessel must initiate the signal and which must respond in an overtaking situation in a narrow channel under International Rules

💭 Think About

• Think about what sound signal you, as the overtaking vessel, must give FIRST to indicate that you intend to pass on the other vessel’s port side in a narrow channel under International Rules. • Then consider what type of blast (short or prolonged) is associated with meeting/crossing maneuvers and what type is used specifically for narrow channel overtaking. • Ask yourself: is there any combination where the first part of the signal clearly says, “I intend to overtake you on your port side,” and the second part is not required from the overtaking vessel but from the vessel being overtaken?

✅ Before You Answer

• Verify in the International Rules (COLREGS), Rule 34(c) what signal an overtaking vessel must sound in a narrow channel when intending to pass on the port side of the other vessel. • Check which type of blasts (short vs prolonged) are used for maneuvering and warning signals versus those used for vessel in restricted visibility (Rule 35), to avoid confusing the two. • Confirm which vessel is required to sound any prolonged blast acknowledgement in a narrow channel overtaking situation, and whether that prolonged part should come from the overtaking or the overtaken vessel.