COLREGs Rule 14 Clarified: No Fixed 3°/6° “Geometric” Test, “and/or” Is Disjunctive, and a Head‑On Classification Persists Until Collision Risk Passes

3.1 Precedents Cited

Evergreen Marine (UK) Ltd v Nautical Challenge Ltd (The Ever Smart) [2021] UKSC 6, [2021] 1 WLR 1436

The Court treated The Ever Smart as the principal modern authority on interpreting and applying COLREGs as an international convention: it endorsed the Supreme Court’s approach (Vienna Convention, ordinary meaning, object/purpose, practicality, uniformity, and comparative sources). It also relied on The Ever Smart for the proposition that Rules 13–15 “cover the ground” of steady bearing collision situations and are mutually exclusive in scope. However, the Court distinguished the appellants’ reliance on The Ever Smart at [56] for “precise specifications”: it did not accept that Rule 14(b) must therefore contain a hidden numerical trigger derived from Annex I.

FMG Hong Kong Shipping Ltd v Owners of the Apollo (The MSC Apollo) [2023] EWHC 328 (Admlty)

The appellants relied on The MSC Apollo for a more restrictive understanding of Rule 14(b) (and related reciprocity points). The Court of Appeal held that the relevant passage did not decide (and was not directed to) the “and/or” meaning or the geometric thesis, and therefore could not carry the weight the appellants placed upon it.

Acacia Ver Navigation Co Ltd v Kezia Ltd (MV Omnia) 78 F.3d 211 (5th Cir. 1996)

This US appellate authority directly supported the Court’s interpretation of Rule 14(b): at night, seeing either both sidelights or masthead lights in line/nearly in line suffices for the Rule 14(b) “deemed” head-on picture. The Court used it as comparative confirmation of the ordinary meaning of “and/or” in an international rule intended for uniform application.

Orduna v The Shipping Controller (1920) 5 Lloyd's L Law Rep 241

Although pre-COLREGs 1972, Orduna was deployed to rebut “instantaneous reclassification” arguments: Viscount Finlay’s warning against treating a developing encounter as having entered a “new phase” prematurely supported the Court’s holding that, once the conditions for a rule’s application arise, they generally persist until the encounter is definitively past that phase.

Gulfcoast Transit Company v MT Anco Princess et al 1978 AMC 471

This Louisiana authority, applied to the predecessor Rule 18 (1960), was cited to support the proposition that once the head-on rule is engaged, a vessel cannot convert it into a different passing regime while the same collision risk continues.

The Lok Vivek and Common Venture [1995] 2 Lloyd's Rep 230

The case was discussed but found not decisive: it did not analyse the “and/or” issue or articulate any strict geometric boundary; it therefore did not advance the appellants’ attempt to read Rule 14(b) through Annex I.

Vienna Convention and travaux cases: Effort Shipping Co Ltd v Linden Management SA (The Giannis NK) [1998] AC 604, Fothergill v. Monarch Airlines Ltd.[1981] AC 251, JTI Polska sp z oo v Jakubowski [2023] UKSC 19

These authorities framed the permissible use of preparatory materials. The Court accepted that travaux may confirm meaning without requiring a “bull’s-eye” intention (JTI Polska), but found that the travaux did not support importing a 3°/6° numerical test into Rule 14(b), and if anything confirmed the textual reading (absence of any linkage between Annex I cut-offs and Rule 14(b)).

Assessors and appellate restraint: The Savina [1976] 2 Lloyd's Law Reports 123; Fage UK Ltd v Chobani UK Ltd [2014] EWCA Civ 5

Coulson LJ used The Savina to caution against an appellate court re-asking the same assessor questions absent a direct challenge to the first-instance assessor’s advice. He invoked Fage to emphasise that appeals should not become attempts to rerun trials—an observation of particular relevance in collision cases where nautical assessor input can tempt parties into re-litigating seamanship evaluations.

3.2 Legal Reasoning

(A) Treaty interpretation: ordinary meaning, practicality, and uniformity

The Court applied the interpretive discipline for international conventions: ordinary meaning in context, in light of object and purpose (safe navigation), and with a premium on rules that can be understood by mariners worldwide. This set the tone for rejecting constructions that are (i) not textually anchored, (ii) operationally complex, or (iii) dependent on technical cross-references that the rules themselves do not make.

(B) Rejection of the “geometric” Rule 14(b) thesis

The appellants’ main innovation was to treat Rule 14(b) phrases (“ahead or nearly ahead”, “masthead lights … nearly in a line”, “and/or both sidelights”) as coded references to the Annex I paragraph 9(a)(i) cut-off for sidelights, generating a fixed 3°/6° trigger. The Court rejected this because:

• Textual silence: Rule 14(b) contains no numerical limit and no cross-reference to Annex I paragraph 9; the language (“nearly”) is inherently evaluative rather than mathematical.
• Structural mismatch: Annex I paragraph 9 is a technical lighting provision (and itself gives a range “between 1 degree and 3 degrees”), not a collision-avoidance classification rule.
• Drafting/interpretive improbability: if a strict numeric test were intended, it would likely have been stated expressly (as in Rule 13(b)’s explicit 22.5°).
• Travaux absence: nothing in preparatory materials linked Rule 14(b) to Annex I cut-off geometry, undermining the plausibility of the implied numerical trigger.
• Appellate posture: once the geometric construction failed, the remaining complaint would effectively be an attack on the trial judge’s evaluative application of “nearly”, which was not permitted within the appeal as framed.

(C) “and/or” in Rule 14(b) is disjunctive

The Court held the natural reading governs: “A and/or B” means A, or B, or both. Accordingly, Rule 14(b) can be satisfied at night by: (i) masthead lights in line/nearly in line, or (ii) both sidelights, or (iii) both configurations together. The Court resisted the appellants’ attempt to rewrite the provision into distance-contingent alternatives (mastheads only pre-sidelight range; sidelights once in range), noting it would introduce uncertainty (when exactly do sidelights become “in range” as a factual matter?) and would do “violence” to the drafting.

(D) Duration: once engaged, Rule 14 persists until risk of collision has passed

The Court accepted that Rule 14 does not expressly include an equivalent to Rule 13(d)’s “subsequent alteration … shall not make … crossing”, but held persistence is inherent: Rule 14’s mandated port-to-port passing and Rule 8’s requirement that avoidance action results in safe passing distance presuppose that the rule continues to govern the developing manoeuvre, rather than switching mid-stream while the same risk continues. Certainty and navigational safety supported a “no reclassification while the same risk persists” approach.

(E) The Court’s deliberate restraint on wider Rule 14 issues

Importantly, the Court refused to decide broader questions (whether Rule 14(b) is exhaustive/definitional; reciprocity in “A vessel” issue; and related bearing/COG complexities) because they were unnecessary to dispose of the appeal. This is a notable feature of the decision: it clarifies two practical operational points (no fixed geometry; “and/or” meaning) and one stability point (duration), but leaves the deeper architecture of Rule 14(a)/(b)/(c) for a future case where determinative.

(F) Procedural reasoning on nautical assessors in the Court of Appeal (PD52C 26B)

Coulson LJ identified a systemic procedural problem: PD52C 26B(1) states that in an appeal from the Admiralty Court in a collision claim or similar seamanship/navigation case, the Court of Appeal “will” (unless otherwise ordered) be assisted by two nautical assessors. The appeal had to be adjourned when the issue was raised late, yet the assessors ultimately were not needed because the appeal turned on legal interpretation rather than seamanship fact-finding.

The judgment sets out practical guidance:

• Appellants should specify in the notice: (a) any first-instance assessor opinion challenged, and (b) why fresh assessors are required on identified grounds.
• Respondents should address this in PD52C paragraph 19 opposition statements.
• The permission judge should decide (and the permission order should state) whether assessors are needed and for which issues.
• Reform is suggested (e.g., replacing “will” with “may”), to avoid mandatory assessor appointment where unnecessary and inconsistent with efficient appellate practice.

3.3 Impact

(A) Substantive navigation law impact

• No “Annex I geometry” shortcut: Parties should not expect Rule 14(b) to be litigated by importing fixed numerical thresholds from sidelight cut-off specifications. “Nearly” remains an evaluative, context-sensitive judgment.
• Clarity on “and/or”: The disjunctive reading reduces tactical arguments seeking to postpone Rule 14(b) engagement until both sidelights are visible, and aligns English law with the US appellate approach in MV Omnia.
• Stability of classification: The Court’s “persists until risk passes” approach discourages mid-encounter reclassification arguments that could produce uncertainty and unsafe oscillation between rules while the same risk continues.
• What remains open: The Court expressly left unanswered whether Rule 14(b) is definitional/exhaustive and issues about reciprocity and Rule 14(c)’s effects on both vessels; future litigation may still test those boundaries.

(B) Litigation and evidential impact

• Appellate framing matters: The Court signalled that once a novel construction fails, appellants cannot morph the appeal into an unpermitted factual challenge to “nearly in line” or “nearly ahead” evaluations.
• Comparative and commentary use: The judgment endorses looking to foreign decisions for uniformity; it also shows courts may prefer mainstream commentary (e.g. Farwell) over post-judgment specialist articles when the text is clear.

(C) Procedural impact (nautical assessors on appeal)

• Immediate practice point: Admiralty collision appellants should treat the assessor issue as a permission-stage topic, not a hearing-day surprise, and should articulate precisely what assessors would be asked to do.
• Potential rule reform: The judgment is an explicit invitation for CPRC to revisit PD52C 26B; until then, parties should expect courts to implement Coulson LJ’s guidance to avoid wasted adjournments and unused assessor appointments.