On 11 February 2015, there was a collision between the respondent's vessel, the Alexandra I, and the appellant's vessel, the Ever Smart. The collision happened at the mouth of the exit channel of the Jebel Ali port in the UAE. At the moment of the collision, the Ever Smart was on its way to the outbound channel from the Jebel Ali port and the Alexandra I was waiting in the designated pilot boarding area for the same pilot on board who had just left the Ever Smart. The collision generated USD 35,000,000 damages to both vessels. Both parties intended to blame the other at fault.

In the first instance judgment, Teare J held that both vessels were at fault. The Ever Smart was at fault due to its violation of rr 5, 7, 9 of the International Regulations for Preventing Collisions at Sea 1972 (COLREGs). The Alexandra I was also found to have been at fault for breaching r 5 of the COLREGs. By applying the principle of causative potency, Teare J held that liability apportioned between the Ever Smart and the Alexandra I at 80% and 20% respectively, given that the causative potency of the Ever Smart's fault was greater than that of the Alexandra I. The Ever Smart appealed.

Held: Appeal dismissed.

Two substantive issues were considered by the Court of Appeal. The first was the applicability of the crossing rule and the second was the application of the principle of causative potency. The Court of Appeal upheld Teare J's conclusion on the first issue and held that r 15 of the COLREGs did not apply in these circumstances.

With regard to the second issue, the Court of Appeal held that the Convention for the Unification of Certain Rules of Law with respect to Collisions between Vessels​ 1910 (Collision Convention 1910) was given domestic effect by the Maritime Conventions Act 1911 (UK) which has in turn been consolidated into the Merchant Shipping Act 1995 (UK). According to art 4 of the Collision Convention 1910, the previous 50:50 division of loss rule had been replaced by the rule of liability in proportion to fault in admiralty cases. 

The Court of Appeal confirmed that both the culpability and the causative potency of the faults established are relevant to the apportionment of liability. Causative potency has two aspects; the first relates to the extent to which the fault contributed to the fact of the collision occurring; the second, to the extent to which the fault contributed to the damage or loss resulting from the collision. Excessive speed is a prime example of a fault likely to contribute to the extent and severity of the damage or loss suffered. A judge is amply entitled to take into account the propensity of excessive speed to increase the damage suffered when undertaking the exercise of apportionment - and thus to have regard in broad terms to the magnitude of the damage sustained. Approached in this manner, the apportionment of liability will constitute, in the words of the judgment in The Dream Star (CMI61), 'a broad, commonsensical and qualitative assessment of the culpability and causative potency of both vessels'. Teare J's approach amounted to 'an unimpeachable broad qualitative assessment of the impact of excessive speed'.