Classification: Who's Who of Classification Societies

A classification society (also known as ‘class’) publishes class rules and technical requirements in relation to design, construction and survey of ships. They also have the authority to apply those rules; verify compliance during construction and periodically through a ship’s life; publish a register of classed ships; and are authorised by a flag administration, as defined by SOLAS, and listed in the IMO database.
Although some owners and builders find classification rules onerous, Paul Martin, principal engineer Det Norske Veritas (DNV), describes them as ‘a system for safeguarding life, property and the environment at sea.’

The societies are also often authorised to act on behalf of various flag administrators to verify that a yacht complies with any appropriate MARPOL, SOLAS, MCA and associated codes.

Class surveyors are trained and certified in accordance with programmes established by their organisations, and periodically undertake refresher and specialist courses. These surveyors are mostly qualified engineers or naval architects.

Yachts designed and built to the appropriate rules of a society apply for a Certificate of Classification from that society, which issues it upon completion of surveys

‘My job is one of verification against a set of requirements during design, construction and operation of the yacht,’ says Martin. DNV’s head offices are in Norway, but the organisation – like all classification societies – has surveyors, like Martin, stationed around the world, who work with customers to ensure compliance throughout the lifetime of the classified vessel.
Yachts designed and built to the appropriate rules of a society apply for a Certificate of Classification from that society, which issues it upon completion of surveys.

Yachts holding such a certificate should not be construed as having a warranty of safety, fitness for purpose or seaworthiness. The certificate just shows that the yacht was constructed according to the societies’ rules. However, maintaining a yacht ‘in-class’ reduces its insurance premium and increases its resale value.

As independent, self-regulating bodies, classification societies have no commercial interest in design, building, ownership, operation, management, maintenance, repairs, insurance or chartering.

Classification society powers

A classification society may assign service notations and some societies define limiting areas for navigation (i.e. coastal waters).

Class may be suspended when:

  • The ship is not operating according to its rule requirements;
  • If it goes to sea with less freeboard than assigned (that’s why load line marks are painted on each hull);
  • When the owner fails to request a survey after damage;
  • When a survey hasn’t been completed by its due date; or
  • When repairs, alterations or conversions affecting class are carried out without requesting a surveyor.


The International Association of Classification Societies (IACS), based in London, represents ten of the most famous societies, including Lloyd’s Register (LR), Det Norske Veritas (DNV), Bureau Veritas (BV), Registro Italiano Navale (RINA), and the American Bureau of Shipping (ABS).

The IACS was given consultative status with the International Maritime Organization (IMO), and remains the only non-governmental organisation with observer status which is able to develop and apply rules.

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