1. As a procedural presupposition, international jurisdiction must be assessed in the light of the material relationship at issue, as described by the plaintiff in his or her initial application, both subjectively (as regards the subjects) and objectively (as regards the claim and cause of action). Or, in other words, by the quid disputatum and quid decidendum – in contrast to what will later become the quid decisum.
2. A commercial yacht is a ship capable of navigating on the sea and used or capable of being used for the transport of persons or goods.
3. Neither the Rome Convention (1) nor the Rome I Regulation (2) contains a special rule on individual contracts of employment on board ships.
4. Continuity, legal certainty, non-discrimination between crew members, and coordination with public law regimes in administrative, technical and social matters justify the preference for the law of the flag of the ship.
5. However, international jurisdiction over individual contracts of employment is governed by the Brussels I Regulation (3), which reflects a particular concern in cases where weaker contractual parties are involved. This also applies to employees, whose protection is ensured not only by material provisions that mitigate their vulnerability but also by rules of jurisdiction that protect these interests.
6. Accordingly, where an employer domiciled in Portugal brings an action for damages against an employee who is a French national domiciled in France for the loss he claims to have suffered as a result of the allegedly wrongful breach of the contract of employment by the employee, whose duties were performed on board the yacht, the French courts, and not the Portuguese courts, have international jurisdiction under Article 22(1) of the Brussels I Regulation to hear and determine that action.