Deviation

Deviation is the vessel's voluntary departure from the agreed route or, failing agreement, from the customary route between the loading and discharge ports. Carriage law treats it strictly, because it unilaterally alters the risk the other parties accepted: an unjustified deviation costs the carrier its statutory defenses and, on some readings, its limits of liability. The Hague-Visby Rules permit two categories, deviation to save or attempt to save life or property at sea, and reasonable deviation, a deliberately elastic notion that has generated abundant case law. In insurance, the classical principle is that cover ceases at the moment of deviation, even if the loss occurs later and is unrelated, a mechanism so blunt that modern policies temper it with a held covered clause against an additional premium. The problem solved is that of a contract priced on a precise passage, whose lengthening changes both the duration of exposure and the nature of the perils met.

From December 2023 onward, attacks in the Red Sea led most large carriers to reroute around the Cape of Good Hope, adding roughly 3,500 nautical miles and ten days at sea to the Asia to Europe run; Suez Canal traffic fell by more than 60% over 2024, and cargo policies responded through their held covered clauses.

changement de voyage, déviation de route