Since the end of 2023, the rerouting of maritime traffic via the Cape of Good Hope to avoid the Red Sea has upended Asia-Europe supply chains: transit lengthened by two to three weeks, additional freight costs and war insurance premiums, cascading delays on sale and carriage contracts. The question that comes up in every file is the same: does this deviation legally excuse the delay, or does it remain a mere commercial risk for whoever suffers it? Six points decide the answer, from the international sale contract to the documentary credit.
1. Mere additional cost is never enough to establish force majeure under the Vienna Convention
Where the sale contract falls under the Vienna Convention of 11 April 1980 (France, China, Japan and Singapore are parties), Article 79 exempts the debtor who proves an impediment beyond its control, unforeseeable and insurmountable. Opinion no. 7 of the CISG Advisory Council draws three cumulative conditions from this: beyond the party’s control, unforeseeable, unavoidable. Under a CIF sale, the choice of carrier and route falling to the seller, the externality argument is weakened. And the First Civil Chamber of the Cour de cassation held, on 17 May 2023 (appeal no. 22-16.290, published in the Bulletin), that the Convention exclusively governs the questions it settles, setting aside Article 1195 of the Civil Code once the parties have not excluded it. A nuance too often neglected must be added: Article 79(5) specifies that the exemption does not release the seller from the contract itself; it protects it only against an award of damages. The buyer retains the right to require performance, to reduce the price, or to avoid the contract if the delay amounts to a fundamental breach within the meaning of Article 25; an exempted seller may therefore still face a perfectly well-founded avoidance. Exemption is not a complete shield.
2. Five concepts not to be confused, on pain of relying on the wrong basis
Force majeure, merely temporary impediment, economic cost increase, imprévision under Article 1195 of the Civil Code and contractual hardship follow distinct regimes, and confusion is expensive in proceedings. Five concepts, five regimes, five outcomes. Under the Vienna Convention, Opinion no. 20 of the CISG Advisory Council even places hardship within the scope of Article 79: performance remains due save established hardship, and the judge may neither adapt the contract nor bring it to an end. The threshold adopted by the reported decisions is high: cost increases of 43%, 100% and even 300% in a German case were held insufficient. A two-to-three-week lengthening of transit is therefore not enough; it would be otherwise for a total and prolonged closure, with no alternative route, on a long-term contract concluded before the crisis. The judge counts in percentages, not in weeks.
3. Maritime deviation is reasonable, and therefore exonerating, only on three cumulative conditions
The Hague-Visby Rules tempered the traditional rigour of maritime law towards deviation: Article IV(4) provides that no reasonable deviation, nor any deviation in saving or attempting to save life or property at sea, shall be deemed a breach of the contract of carriage. Reasonableness is assessed by three criteria: purpose, which must relate to the safety of the ship and not to commercial convenience; proportionality, the Cape rerouting having to be the only safe alternative; and contemporaneity, assessed in the light of the information available at the time of the decision. One consequence is too often ignored: a reasonable deviation exonerates the carrier from the losses resulting from it, but does not transfer to the shipper the burden of additional costs, which depends exclusively on the clauses of the bill of lading or the charterparty. Three distinct obligations must also be identified to target the right ground: delivery in sound condition, an obligation of result resting on the carrier; time, an obligation that exists only if the contract expressly stipulates it, and which is almost always excluded in liner carriage; and diligence in the choice of route, an obligation that subsists in all cases and on which the carrier’s liability is most usefully pursued in the event of a poorly justified deviation. Three obligations, only one truly practicable ground.
4. The BIMCO war risk clauses organise the crisis, but paying the premium does not transfer the risk
Faced with geopolitical risk, stipulation prevails over general law. BIMCO’s model clauses (VOYWAR for voyage charterparties, CONWARTIME for time charterparties, revised in 2025) organise a right of refusal for the owner, before loading or during the voyage, and place on the charterer the reimbursement of additional war risk premiums. But the United Kingdom Supreme Court, in Herculito Maritime Ltd v Gunvor International BV, known as The Polar ([2024] UKSC 2, 24 January 2024), held that the charterer’s reimbursement of a premium does not create an insurance fund excluding the owner’s recourse against cargo interests: only an express stipulation of exclusivity of recourse produces that effect, failing which cargo interests must contribute in general average. Paying the premium is not enough.
5. Cargo insurance excludes delay and makes cover conditional on immediate notice in the event of deviation
Cargo policies rest on the Institute Cargo Clauses of 1 January 2009. Clause 4 excludes any loss due to delay, even where caused by an insured risk: commercial penalties linked to delay are therefore never insured under the ordinary policy. Delay, in marine insurance, does not legally exist. Clause 6 excludes war risks, to be bought back through the Institute War Clauses, whose automatic termination on notice must be watched. Above all, clauses 9 and 10, on termination of the contract of carriage and change of voyage, make the continuation of cover conditional on prompt notice and agreement on the premium: this is the most frequent breaking point, the insured who does not immediately notify its insurer of a deviation risking losing its cover without even realising it.
6. The documentary credit ignores the deviation, and bank force majeure never extends the credit
The documentary credit, governed by the Uniform Customs and Practice version 600, follows the principle of autonomy: the bank examines documents, not the crisis. Article 14 fixes a presentation period which runs from the date of shipment, not arrival; a deviation, however long, therefore does not affect that period. Article 36 deals with banks’ force majeure: they assume no liability for the interruption of their business caused by war or riots, and will not honour, on resumption, credits that expired during that interruption. The beneficiary who could not present its documents during the closure therefore loses the benefit of the credit, save an automatic extension clause stipulated at opening, a drafting precaution that should be systematic on flows transiting a risk zone. Two provisions complete this documentary mechanism: Article 20 allows transhipment, even where the credit prohibits it, provided the goods are containerised and the bill of lading covers the entire carriage; Article 27 requires a transport document clean of any reservation, which a deviation poorly documented by the carrier can jeopardise at the very moment the seller most needs to draw on its credit. The documentary credit does not forgive approximation.
The guide “Red Sea, deviation and supply chain disruption: force majeure or commercial risk?” (May 2026 edition) sets out this whole analytical grid, illustrated by a complete case study of a CIF Le Havre sale rerouted via the Cape, and offers ten contract drafting recommendations. Get the guide
For assistance with maritime litigation or a maritime transaction, see our maritime law page and, on this specific topic, our page on maritime deviation.
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