ROR - Rule 15 Crossing Situation

Section II – Conduct of vessel in sight of one another


Rule 15 - Crossing situation

When two power-driven vessels are crossing so as to involve risk of collision, the vessel which has the other on her own starboard side shall keep out of the way and shall, if the circumstances of the case admit, avoid crossing ahead of the other vessel.


Questions & Answers


Q1. What type of vessels do you need for this rule?
A1. 2 power-driven vessels.

Q2. How do you know who is the give way vessel in a crossing situation?
A2. You're the give way vessel if you have another power-driven vessel on your starboard side.



Q3. When are two vessels crossing each other?
A3.  Crossing situation :

Vessels are near one another.

Vessel is between half a compass point ahead to two compass points abaft the beam.

Vessel’s courses cross one another.


Q4. Two what type of vessel does Rule 15, Crossing situation apply and not apply?
A4. Crossing situation applies to:

Two power-driven vessels crossing.

Crossing situation does not apply to:

Two sailing vessels.

A sailing vessel and a power-driven vessel.

A power-driven vessel and a hampered vessel (NUC, restricted in her ability to manoeuvre, deep draught, fishing).


Q5. What is the most adequate give-way action when two power driven vessels are crossing?
A5. Action by give-way vessel (preferred):

Alter course to starboard to

Pass astern of other vessel

Sound one short blast 


Q6. What should you do in a crossing situation if it is impossible to pass astern of another vessel?
A6. If passing astern is impossible:

Reduce speed, possibly stop and reverse engines (sound three short blasts).

Alter course to port to follow a parallel course .

Make a complete turning circle to port.


Q7. What action should be avoided if the circumstances of the case admit, in a crossing situation if there is risk of collision?
A7.  Avoid:

Crossing ahead

Apply a course alteration to port only for a vessel approaching from near the starboard beam.

Apply a course alteration to starboard for a vessel approaching ahead of the starboard beam.


Q8. When would, in crossing situation with risk of collision, a substantial alteration of course to port, be the best avoiding action.
A8. Avoid :

Crossing ahead

Apply a course alteration to port only for a vessel approaching from near the starboard beam.

Apply a course alteration to starboard for a vessel approaching ahead of the starboard beam.