In order to guarantee epidemiological safety on ships and to prevent the presence of infectious disease agents, every six months vessels floating in international waters, as defined by the International Health Regulations, must carry out an assessment of the competent authority and receive a documentary. If the period of validity of an exemption certificate for the sanitary treatment of a ship or a ship health processing control certificate has expired, the responsible person (ship agent, owner of ship or other authorised person) shall submit an application to the Health Inspectorate. The health inspection specialist shall perform the hygienic on-the-spot assessment of the ship. As a result, an exemption certificate for the control of the sanitary treatment of the ship and/or a certificate for the control of the sanitary treatment of the ship shall be drawn up.