The following report was from the officer of the watch of a large commercial vessel in the Baltic:
– At. 10:30 UTC, My attention was drawn to a tanker calling Sound pilot repeatedly on channel 16. I took the vessel under closer surveillance. Since the vessel was calling for Sound pilot, I figured that she will continue to route D from the Anholt crossing. I noted that her CPA was going to be close if she did not change her course. Keeping in mind that she was the give away vessel, I monitored her progress and kept my course and speed.
– At 10.56 when our TCPA was 9 minutes and CPA 0,4 miles, I gave the vessel a call on ch. 16 and then changed to Channel 6.
From XXXX: Vessel YYYY, this is XXXX on channel 6. I am just wondering what is your intention. Are you going to turn to starboard soon and pass me from my stern?
From YYYY: No I am going to keep my course and speed.
From XXXX: No, this is very dangerous, our CPA is only 0,4 miles. You have to turn to starboard now, I will also turn to starboard.
From YYYY: OK
– At 11.02 UTC. By now, I had alerted our captain to the bridge and we monitored YYYY still slowly turning to PORT and therefore maintaining a collision course with us. When the distance between our ships was about 1 mile and we were still on a collision course, the decision was made that we would turn hard to starboard and get away from YYYY once and for all.
Our turning circle to starboard could be made with less than a 0,15 mile radius and our speed was dropped very quickly to 4 knots.
As we were executing our complete 360 degree turn to starboard, YYYY called us on VHF on channel 16.
From YYYY: XXXX what are you doing?
From XXXX (captain now on the radio): Since you are not following the rules of the road, we are now turning hard to STB
From YYYY: OK
At 11.12 UTC The situation with YYYY was over after we had executed a 360 degree turn to starboard. YYYY continued her journey via route D, calling Sound Pilots on ch. 16 just like before the incident.
We sent a disidentified copy of the report to the manager of vessel YYYY. Their initial response was that “the Master of YYYY strongly complained that the turn to starboard of XXXX had endangered the vessels safe passage and has reduced the CPA from 0.6 to 0.4 miles.
He also explained that his vessel was a give way vessel at 10:30 hrs as stated by the OOW of XXXX but at this time the vessels were at a of about 15 miles.
With a quick estimation, 9 minutes before the CPA the vessels were at a distance of about 4 miles. Thus YYYY was very close to crossing the course of XXXX and therefore there was no need to make a course change.
Therefore the OOW replied that his intention was to maintain his course and speed.
Please also note that the master was on bridge throughout and was monitoring his OOW con.”
CHIRP responded to the manager of YYYY as follows:
“Thank you for having followed up the report. We observe that the issue appears to have arisen due to a different perception between the bridge teams on the two vessels as to the acceptable margin of safety. The bridge team of YYYY considered that it was safe to pass approximately half a mile ahead of XXXX. The bridge team of XXXX considered that this margin of safety was too small.
In CHIRP, we do see the issue of margin of safety reported quite frequently. This was addressed in the editorial to Maritime FEEDBACK Issue No. 18 with the headline “Please Respect My Safety Margin!!!”
CHIRP received a further response from the manager of YYYY stating:
“We fully agree with your comments. Although the bridge team of YYYY considered the CPA of 0.6 miles safe, taking into consideration the area and the recommended routes followed by the vessels, this should have been communicated in advance to the OOW on XXXX.
We consider the issue as a near miss and therefore it will be distributed to all managed vessels in order to be used as training material during the onboard training sessions.”
We have included this correspondence in full because it illustrates how different perceptions of an appropriate margin of safety can lead to concern and possible confusion. We are pleased that the OOW of XXXX reported the incident and that the manager of YYYY followed it up and promulgated it as training material through his fleet. This illustrates the positive benefit of near-miss reporting