The French Supreme Court (Cour de cassation) has provided an important clarification on the legal regime governing the conservatory arrest of ships, reaffirming the primacy and strict application of the International Convention for the Unification of Certain Rules Relating to the Arrest of Seagoing ships, signed in Brussels on 10 May 1952.

Cour de cassation (Commercial Division), 10 September 2025, No. 24-12.424

Background of the Case

Company A had obtained judicial authorization to carry out a conservatory arrest on a vessel owned by Company B, in relation to claims arising from the operation of the ship. Company B challenged the validity of the arrest, seeking its release on the grounds that the measure was contrary to the provisions of the 1952 Brussels Convention and to french law provisions.

Decision of the Court of Appeal

The Court of Appeal upheld the arrest, considering that the conditions under French domestic law — specifically those set out in the Code des transports — had been satisfied, and that the international convention did not preclude the application of national rules.
The Montpellier Court of Appeal further held that the alleged claim did not appear to be sufficiently established in principle to justify the conservatory arrest.

Decision of the Cour de cassation

The Cour de cassation overruled the appellate decision, holding that “the mere allegation by the arresting party of the existence, in its favor, of one of the maritime claims listed in Article 1 of the Brussels Convention of 10 May 1952 is sufficient to establish its right to arrest the ship to which that claim relates.”

French domestic provisions may only apply to determine the procedural authorization of the arrest, but not the substantive validity of the measure.

The Court thus reaffirmed the mandatory and autonomous nature of the Brussels Convention, emphasizing that the validity of a conservatory ship arrest must be assessed solely in light of the Convention’s conditions — particularly those in Article 1, which enumerates the recognized categories of maritime claims. National law cannot add further requirements such as the demonstration of a “sufficiently founded claim.”

Consequently, the Court of Appeal’s decision was overturned for having relied on domestic law to question the existence of the maritime claim.

Indeed article 1 of the 1952 international convention defines the notion of maritime claim :

« Maritime Claim » means a claim arising out of one or more of the following :
(a) damage caused by any ship either in collision or otherwise;
(b) loss of life or personal injury caused by any ship or occurring in connexion with the operation of any ship;
(c) salvage ;
(d) agreement relating to the use or hire of any ship whether by charter-party or otherwise;
(e) agreement relating to the carriage of goods in any ship whether by charter-party or otherwise ;
(f) loss of or damage to goods including baggage carried in any ship ;
(g) general average;
(h) bottomry;
(i) towage ;
(j) pilotage ;
(k) goods or materials wherever supplied to a ship for her operation or main tenance ;
(l) construction, repair or equipment of any ship or dock charges and dues;
(m) wages of Masters, Officers, or crew;
(n) Master’s disbursements, including disbursements made by shippers, charterers or agents on behalf of a ship or her owner ;
(o) disputes as to the title to or ownership of any ship ;
(p) disputes between co-owners of any ship as to the ownership, possession employment or earnings of that ship ;
(q) the mortgage or hypothecation of any ship.

Practical Implications

This ruling reaffirms the primacy of international treaty law over national provisions and strengthens the legal certainty surrounding the conservatory arrest of ships within a harmonized international framework.

Creditors and shipowners must therefore refer exclusively to the 1952 Brussels Convention when initiating or contesting a conservatory arrest. Domestic law cannot impose additional substantive conditions or alter the Convention’s criteria.

The French Supreme Court thus consolidates the coherence and predictability of international maritime law, confirming that the conservatory arrest of sea-going vessels is governed by an autonomous convention-based regime, excluding the concurrent application of domestic rules.

By Olivier VIBERT
Partner at KBESTAN, Business Law Firm based in Évreux and Paris
www.kbestan.fr