In a head-on situation, what is the required maneuver by both vessels?

• A. Maintain course and speed.
• B. Reduce speed to zero.
• C. Alter course to port to pass starboard-to-starboard.
• D. Alter course to starboard to pass port-to-port.

Answer: (D)

In a head-on situation, the ships are required to take action to avoid collision by turning to the right, or starboard. This means both vessels alter their course to starboard so that they pass on each other’s port sides, i.e., pass port-to-port. This standard maneuver comes from COLREGS rules for head-on scenarios and creates a clear, predictable separation path for both vessels.

Maintaining course and speed would keep the collision risk because nothing changes the relative bearing. Reducing speed to zero isn’t the prescribed response in a head-on maneuver, and turning to port would result in passing starboard-to-port, which is not the standard practice in a head-on situation. So the required action is to alter course to starboard to pass port-to-port.