Vessel safety surveys are inspections of the structure and equipment of a vessel to assess the condition of the surveyed items and check that they comply with legal or classification society requirements for insurance and registration. They may occur at any time when there is reason to suspect that the condition has changed significantly since the previous survey, or as a condition of purchase, and the first survey is generally during construction (built under survey) or before first registration. The criteria for acceptance are defined by the licensing or registration authority for a variety of equipment vital to the safe operation of the vessel, such as hull structure, static stability, propulsion machinery, auxiliary machinery, safety equipment, lifting equipment, rigging, ground tackle, etc.
