The blockade is to be considered legally existing, although the winds may occasionally blow off the blockading squadron. It is an accidental change which must take place in every blockade; but the blockade is not therefore suspended.
This axiom is laid down in all books of authority; and the law considers an attempt to take advantage of such an accidental removal as an attempt to break the blockade, and a mere fraud.[185]
When a blockading squadron is driven off by a superior force, the blockade is effectually raised, and it must be renewed by fresh notification, before foreign nations can be affected by an obligation to observe it as a blockade. The mere appearance of another squadron will not renew it, but it must be restored by the measures required for the original imposition of a blockade.[186]
[Sidenote: Second Rule of Blockade.]
It is necessary that the evidence of a blockade should be clear and decisive. A blockade may exist without a public declaration; although a declaration, unsupported by fact, will not be sufficient to establish it. In the War of 1798, the West India Islands were declared under blockade by Admiral Jervis; but the Lords of the Supreme Court held, that as the fact did not support the declaration, a blockade could not be deemed legally to exist. But the fact, on the contrary, duly notified on the spot, is of itself sufficient; for public notifications between governments are meant for the information of individuals; but if the individual is personally informed, that purpose is better obtained than by a public declaration.[187]
Where the vessel sails from a country lying near enough to the blockaded port to have constant information of the blockade, no notice is necessary of its continuance or relaxation; but when the country is at a distance beyond constant information, they may lawfully send their vessels on conjecture that the blockade is broken up, after it has existed a long time.[188] And this is important, as it must be remembered that even the intention to evade blockade is a fraudulent breach of it, and sailing towards the port is an overt act of that intent.[189]
There are two kinds of Blockade. 1. Simple Blockade, i.e. Blockade in Fact; and 2nd., Blockade in Fact, accompanied by a Notification. The first expires by the breaking up intentionally of the blockading squadron. The second, prima facie, does not expire until the repeal of the notification, but it is the duty of the belligerent country directly the blockade ceases, de facto, to revoke its proclamation. And it would appear that a notified blockade would only expire, in fact, after some unnecessary and long neglect to publish this revocation; otherwise neutral nations are bound until such publication.[190]
It has from time to time been stipulated, in treaties between belligerent and neutral countries, (as in the case of the Treaty between Great Britain and the United States, of 1794,) that vessels of the neutral country should not be considered as having notice of a blockade, until they have been duly and respectfully warned off; and it would only be on a second attempt to enter port that they would be liable to be seized. Under such a treaty a neutral vessel might lawfully sail for a blockaded port, knowing it to be blockaded.[191]
[Sidenote: Third Rule of Blockade.]
An act of Violation is essential to a Breach of Blockade; such as, either going in or coming out of the port with a cargo, laden after the commencement of the blockade: or being found so near to the blockaded port as to show, beyond a doubt, that the vessel was endeavouring to run into it: or where the intention is expressly avowed by the papers found on board.[192]