These proceedings arose from a collision between the bulk carriers Kiveli, now renamed Phoenix Dawn, and Afina I off the South coast of Greece. 

Held: Both vessels to blame. Apportionment of liability is 80% to Kiveli and 20% to Afina I.

After an exhaustive examination of the vessels' conduct in light of the Collision Regulations, Bryan J was satisfied that the causative potency of Kiveli's breaches of the Collision Regulations and negligence was very much greater than Afina I's breach.

Section 187 of the Merchant Shipping Act 1995 (UK) [based on art 4 of the Collision Convention 1910] requires that liability should be assessed in proportion to the degree in which each vessel was in fault. The assessment of fault involves consideration of both the blameworthiness and causative potency of both vessels, as well as the relative degree of responsibility of each vessel, so that admiralty judges consider, where one ship is to blame more than the other, how many more times to blame that one vessel is than the other: see The Samco Europe and MSC Prestige [2011] 2 Lloyd's Rep 579 [81].

In The Nordlake and Sea Eagle [2015] EWHC 3605 [149] (Admlty) (CMI2534), Teare J summarised the principles behind the process of assessment as follows:

1. The number of faults on one side or the other is not decisive. It is the nature and quality of a ship’s faults rather their number that matter.
2. Breaches of the obligations imposed on ships in certain defined situations by the Collision Regulations will usually be regarded as seriously culpable. One such rule is the narrow channel rule.
3. Causative potency has two aspects. The first is the extent to which the fault contributed to the fact that the collision occurred. The second is the extent to which fault contributed to the damage resulting from the casualty.
4. In most cases, though not all, it will be right to treat the fault of a ship that creates a situation of difficulty or danger greater than that of the ship which failed to react properly to such situation after it has been created.
5. The fact that a fault consists of a deliberate act or omission may in certain circumstances justify the Court in treating it as more culpable than a fault which consists of omissions only.

As Teare J stated at [151]:

Apportionment pursuant to s. 187 of the Merchant Shipping Act 1995 requires an apportionment of liability in proportion to the degree in which each ship was at fault. This requires an assessment of relative liability as was made clear in a case involving damage caused by the fault of three ships, The Miraflores and The Abadesa [1967] AC 826 [(CMI2274)]. The underlying principle was explained by Sir Henry Brandon thus: 'The correct approach was to consider and weigh the faults of each vessel separately and individually and then to arrive at an apportionment of liability that justly reflected the relative degree of fault as between all three.'

Teare J’s exposition of the principles behind the process of apportionment takes as its starting point an article by Sir Henry Brandon, 'Apportionment of Liability in British Courts under the Maritime Conventions Act 1911'. See also, in this regard, the recent article written by Sir Nigel Teare himself in the LMCLQ entitled, 'Apportionment of liability for damage caused by two or more vessels: is it a simple or a complex exercise?' [2024] LMCLQ 225, which I agree is a 'most authoritative account by a most distinguished judge' as it was described by Cockerill J in the recent case of The X-Press Mahanada and The Burgan [2025] EWHC 712 [141] (Admiralty) (CMI2636).

In this regard Sir Nigel Teare stated:

Apportionment is therefore a crucial part of collision litigation and must, whether it be simple or complex, be conducted carefully …

Let me begin with what you should not do. As has been said in several cases, you do not count the number of faults. The number is not decisive. What matters is their nature and quality, which must be assessed by reference to the two elements of fault: causative potency and blameworthiness ...

Sir Henry Brandon explained that causative potency had two aspects: 'The first aspect is the extent to which the fault concerned contributed to the fact that the collision or other casualty occurred at all. The second aspect is the extent to which the fault concerned contributed to the damage or loss resulting from the collision or other casualty.'

… the causative potency of the vessel which fails to react to a situation of danger which has been created by another vessel will usually be regarded as less than that of the vessel which created the situation of danger.

… the ultimate enquiry in collision litigation is as to the relative causative potency and blameworthiness of each vessel. ...

When comparing the faults of one vessel with those of another, the court must inevitably form a value judgment not only about particular aspects of the vessels’ navigation but also about the vessels’ navigation as a whole … How does one reach the ultimate decision as to relative degrees of fault expressed in terms of fractions or percentages? The court usually asks itself how many more times ship A was at fault than ship B …