Naval Warfare and the Law of the Sea
How the law of armed conflict applies at sea, including blockades, prize law, and the protection of neutral shipping.
War at Sea
The law of naval warfare combines the law of the sea with international humanitarian law. The key framework is the San Remo Manual on International Law Applicable to Armed Conflicts at Sea (1994), which codifies rules on targeting, blockades, neutral shipping, and maritime zones. Unlike some areas of international law, the law of naval warfare has a long history, drawing from centuries of state practice, the Hague Conventions of 1907, and the Geneva Conventions.
The fundamental principles of distinction, proportionality, and military necessity apply at sea as they do on land. Warships may attack enemy military vessels and merchant vessels that are integrated into the enemy's war effort, but they must distinguish these from neutral shipping and civilian vessels. Hospital ships are protected. Attacks on the marine environment that cause widespread, long-term, and severe damage are prohibited.