In order to maintain class the vessel will then have to enter a programme of surveys. This programme will ensure that everything on board the vessel which is material to the safety of the vessel is surveyed in rotation according to a pre-determined timetable. These surveys are scheduled so that every item will have been inspected at the end of a period of 4 years. Once this “cycle” has been completed satisfactorily the vessel will have completed its first “special survey” whereupon the entire “cycle” of surveys begins all over again. Inserted into this programme is a requirement that the vessel is dry docked twice during the survey cycle. However, Societies do give themselves the power to grant an extension of one year (a “Year of Grace”) in a survey cycle bringing it up to 5 years in certain cases where the progress of survey items and the condition of the vessel warrant it. It is also a requirement of Classification Societies that in the event of any accident happening to the ship or its equipment then a Class Surveyor be called in to examine the damage; to advise if the repair has to be done immediately, or whether it can be postponed and if so for how long. If a postponement is granted, full details are entered in the vessel’s records as a “recommendation”. The eventual repair will have to be done under the supervision of the Class Surveyor. It is normal for a ship, once it has been built under the rules of a particular Society, to remain with that Society for its life. There is, however, nothing to stop an Owner from transferring from one society to another, always providing that the two Societies’ building rules are compatible and subject to a full survey by the new Society. The classification societies keep full survey records of all ships which they classify. These records will list all the surveys passed with the date during the current cycle, together with all surveys yet to be passed with the dates when they fall due. The records will also list all repairs done under class requirements and all current “recommendations” for future repairs. Additional Certificates are issued in respect of special characteristics such as the ships ability to carry refrigerated cargo. These records are of great importance to a potential buyer of any second-hand ship and are usually inspected at quite an early stage in negotiations.