Non-compliance with COLREGS Rule 15

Report Text:

Container ship ‘A’, on passage from Kingston Jamaica was heading towards Willemstad Curacao on a course 127° at 7.7 Knots. The Master was monitoring traffic and observed Vessel ‘B’ from far away. With a small CPA and with the intention of not to cross the bow of Vessel ’B’, the Master of the container ship ‘A’ reduced the ship’s speed a small amount, believing to be acting under Rule 8(e) and giving himself more time to assess the situation, he then contacted the Officer of the Watch (OOW) on Vessel ‘B’. When asked about the intentions of Vessel ‘B’, their OOW replied that container ship ‘A’ should pass his stern and B’ would alter course more to his port side. The Master of container ship ‘A’ did not agree and replied that Vessel ‘B should follow COLREGS Rule 15, Unfortunately the OOW on ‘B’ just said ‘thank you’ and changed VHF channel without acknowledgement. The Master on container ship ‘A’ tried to call Vessel ‘B” again on VHF but got no reply.


The pictures of the Automatic Radar Plotting Aid (ARPA) screen show 2 miles range rings showing the crossing ahead was 1.7 miles with CPA 0.57 miles.

Reply from Ship manager:

The OOW of Vessel ‘B’ reported to the Master that he was in contact with the OOW of Containership ‘A’ and in order to avoid the close quarter situation of initial CPA 0.57 nm that could have developed, altered course to port that resulted in a crossing of about 1.8 nm, with CPA of about 1.6 nm. He also stated that the situation was at all times monitored as were VHF channels 6 and 16 and there was not any other call from Container ship ‘A’ after the initial call. However this action was in breach of Rule 15 as the Vessel ‘A’ course should have altered to starboard in order to comply with COLREGs Rule 15.

As corrective and preventive action, the Master was instructed to and has carried out to all Deck officers:

  1. a) Refresh training on COLREGs and Rule 15 in particular.
  2. b) Extraordinary Navigational audit.
  3. c) In addition the case was discussed during an extraordinary Safety Committee meeting with all Deck officers participating.

Furthermore, Company Port captain shall attend the vessel at next port and we will discuss this case and during the debriefing after he signs-off.

CHIRP Comment

The honesty of the reporter and the response from the third party ship manager is much appreciated as it maximizes the opportunity to raise awareness of any safety lessons learned.

The Maritime Advisory Board raised concern over the actions of the OOW on both vessels. The Master of containership ‘A’ was correct when advising the OOW on Vessel ‘B’ that his actions did not comply with COLREGs Rule 15. However the Master of containership ‘A’, by making only a small alteration in speed, took action which was unlikely to be detected by the other ship and therefore was at risk of not being in compliance with Rule 17 (a)(i). Rule 17 has three stages and you must identify and assess each of them:

Rule 17(a) (i): when you are the ‘stand-on vessel’, you must keep your course and speed. You must not do anything unexpected.

Rule 17(a) (ii): ‘as soon as it becomes apparent’ that the give-way vessel is not taking appropriate action, you may take your own action to avoid a collision.

Rule 17(b): when a collision cannot be avoided by the giveway vessel alone, then you must take the best action you can to avoid colliding.

Action under Rule 17(b) must still be in time to avoid a collision so do not leave it too late and do not go to port in a crossing situation under Rule 17(c). If the other ship goes to starboard, as it should, then both ships will turn towards each other. The most prudent action would be to alter course with a round turn to starboard and by turning away would avoid the risk of collision.

The situation appears complex – there appears to be a third and fourth vessel in close proximity to and on the starboard side of vessel ‘B’. OOWs must always “look at the big picture” and assess the possibilities at an early stage, placing their mind in the position of the other vessel(s) to determine if there are complications that will influence and possibly restrict the available actions of any of the ships involved.

Finally do not forget Rule 34(d) manoeuvring and warning signals – the ‘wake up’ signal. Sound your horn and flash your lights at the other vessel. Also think twice before calling on VHF, as that always takes valuable time during which the risk of collision will increase and this has in many instances, resulted in mistaken identity due to incomplete positional referencing.