International Oil Pollution Prevention Certificate (IOPP). Valid for four years confirming that the vessel is equipped with machinery to remove oil from ballast and/or bilge water being pumped overside. International Safety Management Certificate (ISM) shows compliance with the ISM Code. This is dealt with in greater detail later. The four ‘Safety’ certificates are required under the IMO Safety of Life at Sea Conventions (SOLAS), The IOPP certificate relates to the MARPOL Conventions. All these are usually issued on behalf of the Government whose flag the vessel flies by an authorised Classification Society. The surveys needed to issue or renew these certificates are totally independent of the class surveys. Lifting Appliance Certificate – (if the vessel is going to load/discharge with her own gear). This gives details of the cargo gear survey and the safe working loads. De-Ratization Certificate confirming that the vessel is free from all traces of rats. It is issued by a Port Health Authority and is valid for 6 months. Safe Manning Certificate – issued by the Government who flag the vessel flies stating the minimum number, and appropriate ranks of that number, of crew the vessel can sail with. Dangerous Goods Certificate – shows that the vessel meets the requirements and gives details of the separations available for the carriage of Dangerous goods. Grain Book – If the vessel is going to load bulk grain it must carry a book giving details of the vessel’s stability calculations when loading bulk grain which is authenticated by the Government of the country whose flag the vessel flies. Deadweight Scale – This scale shows the immersion of the vessel, i.e draft at any degree of loading.