Artikel 4

(1). Subject to the provisions of paragraph (2), a certificate issued under the authority of a Party in accordance with the provisions of the Convention shall be accepted by the other Parties and regarded for all purposes covered by the Convention as having the same validity as a certificate issued by them.
(2). Every vessel holding a certificate issued under Regulation 7 or 8 is subject, in the ports of other Parties, to control by officers duly authorized by such Parties in so far as this control is directed towards verifying that there is on board a valid certificate. Such certificate shall be accepted unless there are clear grounds for believing that the condition of the vessel or its equipment does not correspond substantially with the particulars of that certificate. In that case, or if there is not a valid certificate, the officer carrying out the control shall forthwith inform the Consul or, in his absence, the diplomatic representative of the Party whose flag the vessel is entitled to fly, of all the circumstances for which corrective action by that Party would be deemed necessary and the facts shall be reported to the Organization. The officer carrying out the control shall take such steps as will ensure that the vessel shall not sail until it can proceed to sea without danger to the vessel or persons on board.