Law of Naval Warfare

NWIP 10-2
Department of the Navy
Office of the Chief of Naval Operations
September 1955


Convention Concerning the Rights and Duties of Neutral Powers in Maritime War - XIII Hague, 1907




Belligerents are bound to respect the sovereign rights of neutral Powers and to abstain, in neutral territory or neutral waters, from all acts which would constitute, on the part of the neutral Powers which knowingly permitted them, a nonfulfillment of their neutrality.


All acts of hostility, including capture and the exercise of the right of visit and search, committed by belligerent vessels of war in the territorial waters of a neutral Power, constitute a violation of neutrality and are strictly forbidden.


When a ship has been captured in the territorial waters of a neutral Power, this Power must, if the prize is still within its jurisdiction, employ the means at its disposal to release the prize with its officers and crew, and to intern the prize crew.

If the prize is not in the jurisdiction of the neutral Power, the captor Government, on the demand of that Power, must liberate the prize with its officers and crew.

(United States adhered to this article with understanding that the last clause implies the duty of a neutral Power to make the demand therein mentioned for the return of a ship captured within the neutral jurisdiction and no longer within that jurisdiction.)


A Prize Court cannot be set up by a belligerent on neutral territory or on board a vessel in neutral waters.


Belligerents are forbidden to use neutral ports and waters as a base of naval operations against their adversaries, and in particular to erect wireless telegraph stations or any apparatus for the purpose of communicating with the belligerent forces on land or sea.


The supply, in any manner, directly or indirectly, by a neutral Power to a belligerent Power, of vessels of war, stores, or war material of any kind whatever, is forbidden.


A neutral Power is not bound to prevent the export or transit, for the use of either belligerent, of arms, stores, or, in general, of anything which can be of use to an army or fleet.


A neutral Government is bound to employ the means at its disposal to prevent the fitting out or arming of every vessel within its jurisdiction which it has reason to believe is intended to cruise, or engage in hostile operations, against a Power with which that Government is at peace. It is also bound to display the same vigilance to prevent the departure from its jurisdiction of every vessel intended to cruise, or engage in hostile operations, which has been, within the said jurisdiction, adapted, entirely or in part for use in war.


A neutral Power must apply impartially to the two belligerents the conditions, restrictions, or prohibitions made by it in regard to the admission into its ports, roadsteads, or territorial waters, of belligerent ships of war or of their prizes.

Nevertheless, a neutral Power may forbid a belligerent vessel which has failed to conform to the orders and regulations made by it, or which has violated neutrality, to enter its ports or roadsteads.


The neutrality of a Power is not affected by the mere passage through its territorial waters of ships of war or prizes belonging to belligerents.


A neutral Power may allow belligerent ships of war to employ its licensed pilots.


In the absence of special provisions to the contrary in the legislation of a neutral Power, belligerent ships of war are forbidden to remain in the ports, roadsteads, or territorial waters of the said Power for more than twenty-four hours, except in the cases covered by the present Convention.


If a Power which has been informed of the outbreak of hostilities learns that a belligerent ship of war is in one of its ports or roadsteads, or in its territorial waters it must notify the said ship to depart within twenty-four hours or within the time prescribed by local regulations.


A belligerent ship of war must not prolong its stay in a neutral port beyond the period legally allowed except on account of damage or stress of weather. It must depart as soon as the cause of the delay is at an end.

The regulations as to the limitation of the length of time which such vessels may remain in neutral ports, roadsteads, or waters, do not apply to ships of war devoted exclusively to religious, scientific, or philanthropic purposes.


In the absence of special provisions to the contrary in the legislation of a neutral Power, the maximum number of ships of war belonging to one belligerent which may be in one of the ports or roadsteads of that Power simultaneously shall be three.


When ships of war belonging to both belligerents are present simultaneously in the same neutral port or roadstead, a period of not less than twenty-four hours must elapse between the departure of the ship belonging to one belligerent and the departure of the ship belonging to the other.

The order of departure is determined by the order of arrival, unless the ship which arrived first is so circumstanced that an extension of its stay is admissible.

A belligerent ship of war can not leave a neutral port or roadstead less than twenty-four hours after the departure of a merchant-ship flying the flag of its adversary.


In neutral ports and roadsteads belligerent ships of war can carry out only such repairs as are absolutely necessary to render them seaworthy, and can not add in any manner whatsoever to their fighting force. The neutral authorities shall decide what repairs are necessary, and these must be carried out with the least possible delay.


Belligerent ships of war can not make use of neutral ports, roadsteads, or territorial waters for replenishing or increasing their supplies of war material or their armament, or for completing their crews.


Belligerent ships of war can not revictual in neutral ports or roadsteads except to complete their normal peace supply.

Similarly these vessels can take only sufficient fuel to enable them to reach the nearest port in their own country. They may, on the other hand, take the fuel necessary to fill up their bunkers properly so called, when in neutral countries which have adopted this method of determining the amount of fuel to be supplied.

If, in accordance with the law of the neutral Power, ships are not supplied with coal until twenty-four hours after their arrival, the lawful duration of their stay is extended by twenty-four hours.


Belligerent ships of war which have taken fuel in a port of a neutral Power can not within the succeeding three months replenish their supply in a port of the same Power.


A prize can be brought into a neutral port only on account of unseaworthiness, stress of weather, or want of fuel or provisions.

It must leave as soon as the circumstances which justified its entry are at an end. If it does not, the neutral Power must order it to leave at once; should it fail to obey, the neutral Power must employ the means at its disposal to release it with its officers and crew and to intern the prize crew.


A neutral Power must, similarly, release a prize brought into one of its ports under circumstances other than those referred to in Article 21.


(This article is not adhered to.)

A neutral Power may allow prizes to enter its ports and roadsteads, whether under convoy or not, when they are brought there to be sequestrated pending the decision of a prize court. It may have the prize taken to another of its ports.

If the prize is convoyed by a ship of war, the prize crew may go on board the convoying ship.

If the prize is not under convoy, the prize crew are left at liberty.


If, notwithstanding the notification of the neutral authorities, a belligerent ship of war does not leave a port where it is not entitled to remain, the neutral Power is entitled to take such measures as it considers necessary to render the ship incapable of taking the sea during the war, and the commanding officer of the ship must facilitate the execution of such measures.

When a belligerent ship is detained by a neutral Power, the officers and crew are likewise detained.

The officers and crew thus detained may be left in the ship or kept either in another ship or on land, and may be subjected to the measures of restriction which it may appear necessary to impose upon them. A sufficient number of men for looking after the vessel must, however, be always left on board.

The officers may be left at liberty on giving their word not to quit the neutral territory without permission.


A neutral Power is bound to exercise such surveillance as the means at its disposal allow to prevent any violation of the provisions of the above Articles in its ports or roadsteads, or in its waters.


The exercise by a neutral Power of the rights laid down in the present Convention can never be considered as an unfriendly act by one or other belligerent who has accepted the Articles relating thereto.


The Contracting Powers shall communicate to each other in due course all laws, proclamations, and other enactments regulating in their respective countries the status of belligerent ships of war in their ports and waters, by means of a communication addressed to the Government of the Netherlands, and forwarded immediately by that Government to the other Contracting Powers.


The provisions of the present Convention do not apply except between Contracting Powers, and only if all the belligerents are parties to the Convention.


The present Convention shall be ratified as soon as possible.

The ratifications shall be deposited at The Hague.

The first deposit of ratifications shall be recorded in a procés-verbal signed by the Representatives of the Powers which take part therein and by the Netherlands Minister for Foreign Affairs.

The subsequent deposits of ratifications shall be made by means of a written notification addressed to the Netherlands Government and accompanied by the instrument of ratification.

A duly certified copy of the procés-verbal relative to the first deposit of ratifications, of the ratifications mentioned in the preceding paragraph, as well as of the instruments of ratification, shall be at once sent by the Netherlands Government, through the diplomatic channel, to the Powers invited to the Second Peace Conference, as well as to the other Powers which shall have adhered to the Convention. In the cases contemplated in the preceding paragraph, the said Government shall inform them at the same time of the date on which it received the notification.


Non-Signatory Powers may adhere to the present Convention.

A Power which desires to adhere notifies in writing its intention to the Netherlands Government, forwarding to it the act of adherence, which shall be deposited in the archives of the said Government.

That Government shall at once transmit to all the other Powers a duly certified copy of the notification as well as of the act of adherence, mentioning the date on which it received the notification.


The present Convention shall take effect in the case of the Powers which were a parties to the first deposit of the ratifications, sixty days after the date of the procés-verbal of that deposit, and, in the case of the Powers who ratify subsequently, or which adhere, sixty days after the notification of their ratification or of their adherence has been received by the Netherlands Government.


In the event of one of the Contracting Powers wishing to denounce the present Convention, the denunciation shall be notified in writing to the Netherlands Government, which shall at once communicate a duly certified copy of the notification to all the other Powers, informing them of the date on which it was received.

The denunciation shall have effect only in regard to the notifying Power, and one year after the notification has been made to the Netherlands Government.


A register kept by the Netherlands Ministry for Foreign Affairs shall give the date of the deposit of ratifications made in virtue of Article 29, paragraphs 3 and 4, as well as the date on which the notifications of adherence (Article 30, paragraph 2) or of denunciation (Article 32, paragraph 1) have been received.

Each Contracting Power is entitled to have access to this register and to be supplied with duly certified extracts from it.

In faith whereof the Plenipotentiaries have appended their signatures to the present Convention.

Done at The Hague, the 18th October, 1907, in a single copy, which shall remain deposited in the archives of the Netherlands Government, and duly certified copies of which shall be sent, through the diplomatic channel, to the Powers which have been invited to the Second Peace Conference.

Source: Department of the Navy. Office of the Chief of Naval Operations. Law of Naval Warfare, NWIP 10-2. September 1955. [see "Appendix B," pp. B-1 to B-6].