Classification surveys. Classification societies carry out various surveys on behalf of governments, particularly in order to ensure that the vessel complies with relevant standards that are required to be met for the issue of essential certificates, such as the Cargo Ship Safety Construction Certificate (SAFCON).
They also carry out annual and other periodical surveys on behalf of the governments to ensure that the vessels are still entitled to hold valid certificates. In addition to these surveys, the societies also require certain surveys to ensure that the ships classed with them are still entitled to retain their class. Surveys may be carried out when it is intended to build a ship for classification these are new construction surveys. Surveys may also be carried out for existing ships, e.g., when they are transferring between societies or when they are being reclassified either after suspension or cancellation of their original classification certificates. If any damage or casualty occurs to a vessel, repairs and alterations may be carried out. These are also surveyed.
The maintaining of standards is ensured by the society in requiring all Vessels to have annual surveys or examinations. Special surveys are also required every four years from the date of the first survey for classification.
Ships less than 15 years old are to be examined in dry dock on any two occasions every five years but with a period not more than three years between dockings. Older ships must be examined in dry dock at two-yearly intervals with extension to 2.5 years when suitable high resistance paint is applied to the underwater portion of the hull. These are docking surveys and are in addition to annual surveys. Surveys may also be carried out as in-water surveys as alternatives to any one of the two docking surveys required every five years. For in water surveys the vessel must be coated with a high resistance paint below the waterline, it must also be of more than 30 metres breadth and less than 10 years old. The in-water survey is carried out under surveillance of a surveyor with the ship at a suitable draught in sheltered waters. The hull below the waterline must be clean. The survey is carried out usually by a diver who is in communication with the surveyor on deck.