Before dawn on 21 August 2017, in the Singapore Strait, the MV Alnic, a Liberian-flagged oil and chemical tanker, collided with the USS John S McCain, a US Navy destroyer. Ten US Navy sailors died and dozens more were injured. Both vessels, and especially the McCain, sustained significant damage.

The Alnic's owner, Energetic Tank Inc (Energetic) petitioned for an exoneration from, or limitation of liability for, the collision. Forty-one Navy sailors or their representatives filed claims for damages against Energetic. So did the US, against which Energetic filed a counterclaim. Subsequently, Energetic and the US agreed upon the monetary value of the damages to the Alnic and to the McCain as USD 442,445 and USD 185 million, respectively.

The District Court concluded that Singapore law would govern both the determination of liability and the calculation of the claimants' damages. After a Phase I bench trial concerning only liability (see CMI655), the District Court denied Energetic's petition for exoneration from, or limitation of, liability. It allocated fault for the collision: 80% to the US and 20% to Energetic. Based on the 20% of damages apportioned to Energetic, the claim of the US against Energetic is USD 36,646,044, plus interest. The District Court then indicated that it would proceed to a Phase II trial, to determine damages to the claimants (see CMI1898). Energetic appealed.

While the appeal was pending, the District Court dismissed Energetic's claims for contribution or indemnity against the US for any damages that might be awarded to the claimants during the Phase II trial as barred by sovereign immunity. Energetic also appealed this order.

Following its decision on sovereign immunity, the District Court retroactively certified that its earlier opinion on the apportionment of liability was a final judgment as to the US. Subsequently, several claimants cross-appealed, challenging the District Court's earlier decision applying Singapore law to the calculation of damages.

Held: There is no error in either the District Court's apportionment of liability under Singapore law or its sovereign immunity ruling. The District Court's judgment and order on Energetic's appeals are therefore affirmed. The District Court's choice-of-law ruling is a non-appealable collateral order. The claimants' cross-appeals for lack of jurisdiction are therefore dismissed.

The District Court applied Singapore law in determining the US' and Energetic's liability for the collision. No party contests that decision. We join the District Court in applying Singapore law.

In this case, the standards for determining liability for the collision are clear. That is because '[t]he elements of negligence under Singapore law are substantially the same as those under United States admiralty law'. The relevant duty is "the exercise of 'good seamanship' - ie, 'the exercise of reasonable skill or care expected of a competent/prudent seaman to prevent the vessel from doing injury'.

In evaluating negligence under this standard, we follow the Singapore courts in treating decisions of 'common law courts around the world' - and especially of English courts - as persuasive authority. As expert testimony indicated, this reflects that 'Singapore's legal system is built on a two hundred years of the English common law tradition' and 'Singapore law on maritime collisions [remains] closely similar to English law' in relevant respects.

Under Singapore law, liability in maritime collision cases must be apportioned 'to the degree in which each ship was in fault': Maritime Conventions Act 1911, s 1(1). The Collision Convention 1910, which Singapore has ratified, imposes a similar framework. Singapore courts have made clear that 'the determinative factor for apportionment is ... the comparative appreciation of the degree in which the respective faults of the vessels have contributed to the result of the collision": The Dream Star [2018] 4 SLR 473 [125] (CMI61). Although allocation of liability requires considering 'the nature and quality of a ship's faults': ibid [126], '[i]t is not a question of distributing moral blame': ibid [125]. Thus, only legal fault - here, negligence - is relevant.

The District Court correctly stated Singapore law governing apportionment of liability: 'Under the Brussels Convention, courts consider both "the relative culpability of each vessel and the relative extent to which the culpability of each caused the collision"': id 359-60.

The District Court allocated no fault to the Alnic for its actions in the 112 seconds after the McCain signaled red-over-red. We find neither clear error in this apportionment, nor error in the District Court's underlying legal analysis.