6.—(1) Paragraphs (2) and (3) of this regulation do not apply to a ro-ro passenger ship operating exclusively in sea areas where the significant wave height is equal to or lower than 1.5 metres.
(2) A United Kingdom ro-ro passenger ship to which the requirements of regulation 4 apply shall carry a certificate, issued by the Secretary of State in accordance with the guidelines set out in Annex II of the Directive (in so far as those guidelines are practicable and compatible with the design of that ship), which:
(a)confirms that the ship complies with the stability requirements of regulation 4, and
(b)indicates the highest value of significant wave height up to which the ship satisfies the requirements of regulation 4.
(3) A non-United Kingdom ro-ro passenger ship to which the requirements of regulation 4 apply shall carry a certificate issued by the administration of the EEA State or third country whose flag it flies which:
(a)confirms that the ship complies with the stability requirements of regulation 4, and
(b)indicates the highest value of significant wave height up to which the ship satisfies the requirements of regulation 4.
(4) A ship or high speed craft to which the stability requirements specified in Merchant Shipping Notice 1790 which are the stability requirements of the Stockholm Agreement apply shall carry a certificate, issued:
(a)if it is a United Kingdom ship or craft, by the Secretary of State, and
(b)if it is any other ship or craft, by the administration of the EEA State or third country whose flag it flies,
which confirms that the ship or high speed craft complies with the stability requirements of the Stockholm Agreement and indicates the highest value of significant wave height up to which the ship satisfies those requirements.
(5) A ship or high speed craft shall not operate in a sea area with a higher value of significant wave height than that shown on its certificate.