The "Navigator Aries"

• Jurisdiction: Singapore
• Judge: Judith Prakash JCA
• Judgment Date: 07 July 2023
• Neutral Citation: [2023] SGCA 20
• Court: Court of Appeal (Singapore)
• Docket Number: Civil Appeal No 45 of 2022
• Hearing Date: 03 April 2023
• Citation: [2023] SGCA 20
• Year: 2023
• Plaintiff Counsel: Seah Lee Guan Collin, Jonathan Lim Shi Cao and Choi Yee Hang Ian (Resource Law LLC)
• Defendant Counsel: Mohamed Goush s/o Marikan (Goush Marikan Law Practice) and Mohd Munir Marican (Marican & Associates)
• Subject Matter: Admiralty and Shipping,Collision
• Published date: 13 July 2023

Steven Chong JCA (delivering the judgment of the court): Introduction

This appeal concerns a collision in the Surabaya Strait, Indonesia (the “Strait”) between two vessels travelling on reciprocal courses. The appellant’s vessel, the Navigator Aries (the “NA”), is a liquefied petroleum gas (“LPG”) tanker with a gross registered tonnage of 18,311mt. The respondent’s vessel, the Leo Perdana (the “LP”), is a container vessel with a gross registered tonnage of 27,104mt. The collision occurred just before midnight (local time) on 28 June 2015. The impact left both vessels badly damaged, with a fire breaking out on the NA.

The trial of a collision case between two large vessels underway typically generates considerable evidence, both factual and expert, and documents. This was the case here although the material events were largely focused on the last few minutes leading up to the collision, with the last minute proving to be the most critical. Right up to the last minute prior to the collision, the bridge on each vessel was relatively calm. Both vessels were under compulsory pilotage and it appeared that they were confident of safely passing each other port-to-port as agreed.

About a minute prior to the collision, the LP experienced a significant sheer to port onto the path of the NA. The LP attempted to use her Very High Frequency (“VHF”) radio to inform the NA that her “steering [was] not responding”. Shortly thereafter, the NA noticed the sheer and took avoidance action by altering hard-to-starboard, but the collision could not be avoided.

The High Court judge (the “Judge”) found that the proximate cause of the collision was the port sheer of the LP. In turn, the sheer resulted from hydrodynamic interaction between the LP and a bank lying on her starboard side – a phenomenon known as “bow cushion effect”. These findings are not disputed by the parties on appeal. The outcome of the appeal largely depends on the proper attribution of fault for the occurrence of the port sheer. Key to this inquiry is whether the LP knew or ought to have known some time before the above VHF communication (at [3] above) that some hydrodynamic force was already in play which impeded her ability to respond to helm action. This in turn would have a crucial bearing on the propriety of the actions or omissions of those onboard the LP.

Both vessels, not unexpectedly, provided drastically different accounts of the events leading to the collision. However, both vessels were equipped with navigational aids where important data was contemporaneously recorded. As we will explain below, this data, which embodied vital objective evidence of the events onboard both vessels leading up to the collision, was most helpful in our analysis of the relative faults of both vessels.

The Judge apportioned liability at 70:30 in favour of the LP. After careful examination of the evidence, for the reasons set out below, we disagree with the Judge and hold that both vessels were equally to blame for the collision, and accordingly, apportion liability at 50:50.

This case also offers an opportunity for us to clarify the proper interpretation of Rule 9(a) of the International Regulations for Preventing Collisions at Sea 1972 (the “COLREGS”), which both vessels allegedly breached. The COLREGS have been incorporated as the collision regulations for the purposes of the Merchant Shipping Act (Cap 179, 1996 Rev Ed), pursuant to reg 3 of the Merchant Shipping (Prevention of Collisions at Sea) Regulations (Cap 179, Rg 10, 1990 Rev Ed). In particular, we will examine whether Rule 9(a) should be interpreted in a manner which is consistent with or different from its predecessor provision, ie, Rule 25(a) of the International Regulations for Preventing Collisions at Sea 1960 (the “1960 Collision Regulations”).

Background facts The vessels

The NA is an LPG carrier registered in Surabaya, Indonesia. She is about 160m in overall length and 25.6m in breadth (beam). She was carrying about 59 tonnes of LPG at the material time, and indicated that she was carrying dangerous cargo by displaying an all round red light (in addition to the regulation masthead lights, sidelights and sternlights that both vessels were displaying). Her drafts at departure were 5.5m forward and 6.2m aft.

The LP is a fully cellular container ship flying the Panama flag. She is the larger of the two vessels, measuring about 200m in overall length and 32.2m in breadth (moulded). She was laden with containers weighing around 17,200mt at the material time. For reasons that will become clearer later (at [66] and [170] below), it is relevant to note that the LP’s drafts at departure were 8.54m forward and 8.65m aft.

The primary means of position monitoring on both vessels were actual Standard Nautical Charts (SNC), and not Electronic Chart Display and Information System (ECDIS). Both vessels were using the British Admiralty Chart No 975 (26 April 2012 edition) (“BA Chart 975”) of the Strait.

The vessels’ voyages

The collision occurred within the Strait, which is approximately 50nm long and passes between the northeast coast of Java and the island of Madura. Within the Strait, the weather was good and visibility was about six miles. There was a northerly current associated with the ebbing tide, which was about 1.22m high.

The NA was on a voyage from Gospier jetty in Surabaya, to Kalbut at the eastern end of Java. She was thus travelling outbound on a northerly voyage, towards the Strait’s northern entrance.

The LP was on a voyage from the Evergreen container terminal in Kaohsiung, Taiwan, to Tanjung Perak in Surabaya. She was travelling inbound on a southerly voyage from the Strait’s northern entrance.

The vessels were thus on reciprocal courses within the Strait. This is illustrated in the following plot prepared by the respondent’s experts, which shows the actual track taken by each vessel (with timestamps reflecting local time):

The period of the voyage starting from 23:12 hours is most relevant to the collision. The vessels’ tracks for this period have been mapped out by the appellant’s experts using the vessels’ automatic identification system (“AIS”) data (with the AIS heading data generated from each vessel’s gyro compass):

Objective evidence on the vessels’ voyages was adduced in several forms. Apart from AIS data, the vessels’ voyage data recorders (“VDR”) captured important information such as each vessel’s speed, heading and rudder angle (“VDR data tables”). Conversations that took place in each vessel’s wheelhouse and communications over VHF radio were also recorded. Most of these conversations took place in Bahasa Indonesia or Tagalog, but they have been translated and transcribed for the purposes of these proceedings.

Additionally, each vessel was equipped with two sets of Automatic Radar Plotting Aid (“ARPA”) radar, namely an X-Band and an S-Band radar. Screengrabs of the output from each vessel’s X-Band radar were automatically captured and saved at 15s intervals. The accuracy of this data is undisputed. The respondent’s navigation expert, Captain Keith Hart (“Capt Hart”), opined that any positional errors concerning the LP and the NA were at most of a few metres, and any timing errors, of a few seconds. As will be seen below, these radar screengrabs provide critical insight into the relative positions of both vessels with respect to the material events.

We use this opportunity to sketch out some key aspects of the LP’s radar, using this screengrab taken at 23:11:21 hours as an example: The radar was set to north-up mode with relative motion, and a 3nm range. The green echo enclosed by a dashed circle is the LP. The green echo identified as “AIS14” (in this instance) is the NA. The thin white line (annotated in green) is the LP’s heading marker. This is also indicated at the top right-hand corner of the screengrab, and is 202.3° in this instance. The thick white line (annotated in blue) is the LP’s projected vector (based on a 6min projection). This is calculated using ARPA. The dashed white line (annotated in pink) is the LP’s electronic bearing line (EBL1), which reflects the LP’s planned change of heading. This is also indicated near the bottom right-hand corner of the screengrab, and is 209.8° in this instance.

The narrow channel

The Strait was marked by lateral buoys. Around the site of the collision, these were laid out in a staggered pattern. It is undisputed that the buoyed channel represented a narrow channel to which Rule 9 of the COLREGS applied. Under the Strait’s buoyage system, northbound vessels were to keep the red lateral buoys on their starboard side, and southbound vessels were to keep such buoys on their port side.

Within the buoyed channel was a dredged channel (the “Dredged Channel”). Dredging works took place from 2014 to May 2015, to deepen part of the buoyed channel from 9.5m to up to 13m (chart datum), and to widen the width of this dredged section from 100m to 150m (this distance excludes slopes extending outwards on either side of the Dredged Channel). This is the section that appears mainly in green in the following overlaid chart:

The dredging works were completed shortly before the collision and a post-dredging bathymetric survey was conducted from 18 June to 26 June 2015. In other words, the survey concluded just two days before the collision occurred on 28 June 2015. The BA Chart 975 used by both vessels did not reflect the Dredged Channel’s post-dredging bathymetry. Nevertheless, the parties’ navigation experts considered that the pilots on board both vessels would likely have been familiar with the dredged conditions.

BA Chart 975 also reflected a two-way recommended track (the “Recommended Track”). There are no known local regulations mandating its use. The Recommended Track essentially ran along the centre of the Dredged Channel, such that the Dredged...