Naval Warfare and IHL
The rules governing warfare at sea, from blockades to hospital ships to submarine warfare.
IHL at Sea
Naval warfare is governed by a combination of treaty law, customary IHL, and the San Remo Manual on International Law Applicable to Armed Conflicts at Sea (1994). The Second Geneva Convention specifically protects wounded, sick, and shipwrecked members of armed forces at sea. Hospital ships are protected from attack and may not be used for military purposes.
The fundamental principles of IHL apply at sea: distinction between military and civilian vessels, proportionality in attacks, and precautions to minimize civilian harm. Merchant ships are civilian objects and cannot be attacked unless they contribute to the enemy's military action. The sinking of neutral or civilian ships without ensuring the safety of passengers and crew has been prohibited since the 1936 London Protocol.