QCR Autumn 2019: Obligations of a vessel crossing traffic lanes in a Traffic Separation Scheme under COLREGS and the proper use of VHF radio communications between passing vessels

The “Mount Apo” and the “Hanjin Ras Laffan” [2019] SGHC 57


The “Hanjin Ras Laffan” was transiting the Singapore Strait from East to West while the “Mount Apo” (“Mt Apo”) was attempting to cross the westbound lane of the Traffic Separation Scheme (“TSS”) in the Singapore Strait in order to reach the eastbound lane to continue its journey eastwards. “Mt Apo” entered the TSS at a shallow angle of 32 degrees from the northern boundary of the TSS.

Minutes before the collision, the “Hanjin Ras Laffan” called “Mt Apo” on the VHF (the “9:55 Conversation”):

Hanjin Ras Laffan: Mount Apo. Mount Apo. This is Hanjin Ras Laffan.

Mt Apo: Yes, Mount Apo, go ahead.

Hanjin Ras Laffan: This is Hanjin Ras Laffan, what is your intention? Green-to-green, green-to-green.

Mt Apo: We are now stopped our engine already.

Hanjin Ras Laffan: Are you, are you stopped now, the engine?

Mt Apo: Yes sir. Stopped engine to make you pass our bow.

Hanjin Ras Laffan: Oh very dangerous sir!

Less than four minutes after the conversation ended, the vessels collided. As neither side contended that the other was solely to blame for the collision, the central issue to be determined was the apportionment of liability.


After considering the culpability and causative potency of both vessels, the Court apportioned liability 60:40 in favour of the “Hanjin Ras Laffan”.

The Court held, inter alia, as follows:

1. “Mt Apo” was at fault for crossing the TSS when it was unsafe to do so, contrary to Rule 10(c) of the COLREGS[1]

In finding that it was unsafe for “Mt Apo” to cross the TSS at the time she did so, the Court considered the Master’s admission that it was not prudent to cross at the time she did and the Master’s agreement with at least two other options that he could have taken.

The inquiry into whether it was unsafe to cross must centre on what the traffic condition was in the TSS, and not on whether the vessel intending to cross had other options. An unsafe crossing does not become safe merely because there were no other options open to the vessel at the time.

2. “Mt Apo” was at fault for crossing the TSS at the shallow angle of 32 degrees

As there were no good reasons for “Mt Apo” to cross at a shallow angle, “Mt Apo” was in breach of Rule 10(c) of the COLREGS.

A Master should always seek to follow a heading at 90 degrees to the general direction of traffic flow, except where the safety of navigation requires otherwise, or for other good reasons. Good seamanship also requires the master to line his ship up very early, to edge up to the boundary of the traffic lane, maintaining the correct broad angle, and then to cross it at a safe speed, when it is clear, even if this adds to the length of the passage.

3. “Hanjin Ras Laffan”’s initiation of the 9:55 Conversation was a misuse of VHF

The Court found that it was unnecessary for the Master of the “Hanjin Ras Laffan” to initiate the 9:55 Conversation since he had already observed “Mt Apo” entering the TSS before that. His attempt to arrange an agreement for a green-to-green passing was a misuse of the VHF, as this was contrary to Rule 15[2] of the COLREGS.

The use of VHF will not be criticised if the course of action contemplated in the VHF conversation is consistent with the COLREGS. The Court cautioned that compliance with the COLREGs should remain the primary means for averting collision[3]. Mariners ought to be aware of the risks associated with the use of VHF (such as uncertainty over the identity of vessels, uncertainty over the interpretation of messages, distraction from keeping a proper look-out and loss of time to take avoidance action), before resorting to VHF communication when passing other vessels or approaching a close quarters situation.

4. “Hanjin Ras Laffan” was at fault for her incremental alterations to course and speed after the 9:55 Conversation

After the 9:55 Conversation, “Hanjin Ras Laffan” made a series of minor alterations of course to port as well as incremental reductions of speed from 12 knots to 10.7 knots.

The Court found that it would have been more prudent for the Master to make bolder alterations of course and speed, and the failure to do so (contrary to Rule 8(b)[4] of the COLREGS) would have caused confusion to “Mt Apo” about his intentions.

5. “Mt Apo” was at fault for not reducing her speed more decisively after informing “Hanjin Ras Laffan” in the 9:55 Conversation that they would let “Hanjin Ras Laffan” pass her bow

The Court found that the “Mt Apo” was at fault for failing to act consistently with the information she had provided to “Hanjin Ras Laffan”. A vessel is at fault for not acting in accordance with information she has provided to the other vessel about her intended course of action.

From 9:55 a.m. to 9:57 a.m., “Mt Apo”’s speed reduced very slightly, from 7.8 knots to 7.1 knots. Assuming that the “Mt Apo”’s plan was to slow down for “Hanjin Ras Laffan” to pass her bow as indicated in her VHF reply, this very gradual rate of reduction would not have been sufficient for “Hanjin Ras Laffan” to pass “Mt Apo”’s bow safely.


This case sets out the obligations of a vessel crossing traffic lanes in a TSS under the COLREGS and provides examples of what good seamanship entails. It also serves as a reminder of the risks associated with the use of VHF and emphasises that COLREGS will be more effective to avert a collision, rather than the use of VHF communications.

The judgment for this case may be downloaded from: https://www.supremecourt.gov.sg/docs/default-source/module-document/judgement/owner-of-the-vessel(s)-mount-apo-(imo-no-9493755)-v-owner-and-or-demise-charterer-of-the-vessel-hanjin-ras-laffan-(imo-no-9176008).pdf

[1] Rule 10(c) of COLREGS: A vessel shall so far as practicable avoid crossing traffic lanes, but if obliged to do so shall cross on a heading as nearly as practicable at right angles to the general direction of traffic flow.

[2] Rule 15 of COLREGS: 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.

[3] See also, MPA’s Port Marine Circular No 18 of 2005- “Caution on the use of VHF radio in collision avoidance”: https://www.mpa.gov.sg/web/portal/home/port-of-singapore/circulars-and-notices/port-marine-circulars/detail/pc05-18

[4] Rule 8(b) of COLREGS: Any alteration of course and/or speed to avoid collision shall, if the circumstances of the case admit, be large enough to be readily apparent to another vessel observing visually or by radar; a succession of small alterations of course and/or speed should be avoided.