One of the dilemmas facing Masters and bridge watch keepers is what to do when faced with a situation where the ship's obligations under the Collision Regulations (Colregs) appear to conflict.

The UK Court of Appeal recently clarified one such dilemma in the case of Evergreen Marine v Nautical Challenge 1 when it upheld the first instance judgment of the Admiralty Judge Nigel Teare QC (sitting with Elder Brethren Captain Stephen Gobbi and Captain Nigel Hope as Nautical Assessors). The decision of the Court of Appeal (Lords Justices Gross, Levison and Leggatt) provides clear guidance on the interaction (and interpretation) of the crossing rule (Rule 15) and narrow channel rule (Rule 9) in circumstances when they appear to conflict.

Although fact dependent, in circumstances where one vessel is approaching a narrow channel so as to enter into it, and another vessel is transiting outbound from the same channel, the decision clarifies that the narrow channel rule, which requires that each vessel be positioned to keep as near to the side of the channel on its starboard side as possible, will be applied and in the event of conflict the crossing rule disapplied. In particular, the crossing rule will not relieve a vessel from liability in circumstances where it has breached the narrow channel rule.

The Court of Appeal's decision also confirms the judicial approach to the apportionment of liability; particularly in respect of 'causative potency' and the increased culpability as a result of excessive speed.


Shortly before midnight on 11 February 2015, a serious collision occurred outside the dredged channel to the port of Jebel Ali (UAE) between Alexandra 1, a VLCC described by its master as "a hog on ice with no skates" and Ever Smart, a container ship which was "a Mercedes" in comparison. There were clear night skies and good visibility of 10-12 miles. The wind was force 3 and blowing easterly to east north easterly.

Ever Smart was proceeding in a north westerly direction outbound along the approach channel and had just disembarked her pilot. Alexandra 1 was waiting to embark the same pilot in the designated pilot boarding area at the NW end of the channel such that Ever Smart was on her starboard bow. The port bow of Ever Smart struck the starboard bow of Alexandra 1 at an angle of about 40 degrees, leading aft on Ever Smart. At the time of the collision the speed of Ever Smart was 12.4 knots, whereas the speed of Alexandra 1 was 2.4 knots.

The collision caused ships amounted to over US$35 million in damage to the two ships, prompting both parties to claim that the other was at fault.

Decision at first instance

The principal dispute between the parties was whether, for the purposes of the Colregs, Rule 15 or Rule 9 applied in the circumstance.

Counsel for Ever Smart argued that Rule 15 (crossing situation) applied; requiring that Alexandra 1 (travelling on an Easterly course with Ever Smart on her starboard side) keep out of the way of, and avoid crossing ahead of, Ever Smart.

Counsel for Alexandra 1 conversely argued that Rule 15 had no application in a situation where one vessel was navigating along a narrow channel and another vessel was navigating towards that channel with a view to entering it. In such circumstances, Rule 9 should apply which would require that Ever Smart keep to the outer limit of the channel to her starboard side so far as is safe and practicable, and had it done so this would have avoided the collision.

At first instance, Teare J held that Rule 15 did not bind Alexandra 1 when she approached the narrow channel leading to Jebel Ali because she was not on a sufficiently constant direction or heading to be on a course at the relevant time and, consequently, that Alexandra 1 was not under a duty to keep out of the way of Ever Smart.

Teare J concluded that, as a matter of good seamanship, Alexandra 1 was under a duty to navigate in such a manner that, when she reached the channel, she would be on the starboard side in accordance with Rule 9. In consultation with Captain Stephen Gobbi and Captain Nigel Hope, Teare J also concluded that Alexandra 1 had acted reasonably and in good seamanship by approaching the first buoys (marking the end of the approach channel) and keeping close to her own (starboard) side of the entrance channel whilst Ever Smart was still in the channel; subject to keeping good aural and visual lookout.

Ever Smart was therefore at fault due to in respect of:

  1. breaching Rule 9 of the Colregs by not keeping to the starboard side of the narrow channel;
  2. keeping a defective radar and visual lookout (Rule 5) and making assumptions on the basis of scanty information (Rule 7); and
  3. proceeding at an excessive speed, a direct consequence of her failure to keep a good lookout.

In respect of the breach of Rule 5, Teare J accepted further advice from the Elder Brethren that Ever Smart had been at fault in not acquiring Alexandra 1 as an ARPA target, timeously or not.

Notwithstanding the various faults of Ever Smart, Alexandra 1 was found to have been at fault for failing to keep a good aural lookout (Rule 5), leading to its misunderstanding of a VHF conversation between Port Control and a local tug, whereby Alexandra 1 believed that Ever Smart was being told to go around the 'waiting tanker' (Alexandra 1) when in actual fact this command was being directed to the local tug and not Ever Smart.

In apportioning liability between the parties (given that both vessels were found to be at fault), Teare J employed the principle of 'causative potency'2 and adjudged that although both parties contributed to the fact that the collision occurred (for their respective failures to comply with the Colregs), Ever Smart had contributed far more to the damage sustained from the collision as a result of her excessive speed. Teare J therefore held that the causative potency of Ever Smart's fault was greater than that of Alexandra 1 and found Ever Smart to be 80 per cent liable for the collision.

Counsel for Ever Smart appealed this decision.

Decision on appeal

The principal issues on appeal concerning seamanship were as follows:

  1. Issue 1: the applicability of the crossing rule; and
  2. Issue 2: the application of the principle of causative potency.

With regard to Issue 1, Lord Justice Gross giving the leading judgment for the Court of Appeal agreed with Teare J's conclusion that Rule 15 did not apply in the circumstances.

Whilst Alexandra 1 had been proceeding at slow speed in a broadly east south easterly direction towards the entrance of the channel, Gross LJ noted that her course made good varied between 84 and 112 degrees and, as such, Alexandra 1 could not be considered to have been 'on a course' for the purposes of Rules 15 and 17 of the Colregs. Acknowledging that the Colregs are practical rules having, as their primary object, the prevention of collisions at sea, the Court of Appeal was satisfied that the navigation of Ever Smart was governed by Rule 9, and the approach of Alexandra 1 was governed by the principles of good seamanship; having regard for the requirements of Rule 9.

Counsel for Ever Smart had argued that Teare J's conclusion had not been stress-tested in a hypothetical scenario in which the inbound vessel was approaching from East-West as opposed to West-East (an East-West Scenario) and that, absent the application of Rule 15, there was subsequently no clarity as to priority, putting safety at risk.

Given that this submission raised a question of seamanship, the Court of Appeal sought independent advice from Elder Brethren Rear Admiral David Snelson and Captain Duncan Glass, acting as Nautical Assessors. The Elder Brethren advised that in an East-West Scenario, a prudent mariner in an outbound vessel from Jebel Ali would, amongst other things, keep a sharp look out, ensure compliance with Rule 9, proceed at a safe speed and use VHF to contact the incoming vessel to advise on its own intentions.

Although the Court of Appeal was not strictly required to determine the applicability of the rules in an East-West Scenario, Gross LJ accepted the advice of the Elder Brethren as to the actions of a prudent mariner in an East-West Scenario and was amply satisfied that the East-West scenario did not undermine the first instance judgment on the actual West-East encounter. Likewise, Gross LJ accepted the earlier advice as to the good seamanship of Alexandra 1 in approaching buoys no.1 whilst Ever Smart was still in the approach channel. No doubt, the fact that the Alexandra 1 was approaching prudently at a speed of 2.4 knots was an important factor. The Court of Appeal therefore approved Teare J's judgment on Issue 1.

In respect of Issue 2, the Court of Appeal approved the apportionment of liability 80% against Ever Smart. Gross LJ was satisfied that Teare J was entitled to take into account the propensity of excessive speed to increase damage resulting from a casualty and had therefore been correct in adopting "a broad, commonsensical and qualitative assessment of the culpability and causative potency of both vessels". Gross LJ went further in stating that "excessive speed is a prime example of a fault likely to contribute to the extent and severity of the damage or loss suffered", confirming that speed is a key consideration to the court when apportioning liability.


The decision in Evergreen Marine v Nautical Challenge confirms that, in circumstances where one vessel is approaching a narrow channel so as to enter into it and another vessel is transiting outbound from the same channel, the narrow channel rule will be applied and the crossing rule will be disapplied (subject to the facts in each casualty). The crossing rule will not be applied to relieve a vessel from liability when it violated the narrow channel rule.

The decision of the Court of Appeal also highlights that, when considering the causative potency of multiple factors giving rise to a collision (and the damage resulting therefrom), the court will apportion liability against a vessel navigating at excessive speed if, following a detailed assessment, excessive speed is determined to be a contributing factor to damage and subsequent loss.


1 Evergreen Marine (UK) Ltd. v Nautical Challenge LTD [2018] EWCA Civ 2173

2 'Causative potency' was developed as a principle by Teare J in the earlier case of Owners and/or Demise Charteres of the Nordlake v Owners of the SeaEagle (now named Elbella) [2015] EWHC 3605

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