What is classification and why is it that flag states require that a vessel is classified and that classification is maintained.


Classification is basically nothing more than the verification of :

  • structural strength and integrity of essential parts of the ship’s hull and its appendages;
  • the reliability and function of the propulsion and steering systems, power generation and those other features and auxiliary systems.

Classification does not cover :

  • every piece of structure or item of equipment on board a vessel;
  • operational elements.


Once a ship is classified, many flag states require that the classification is maintained, which means that class surveys are conducted periodically to determine if the classification requirements are still being met.


The classification of an existing ship should not be taken lightly. Design plans and related documents have to be submitted, the initial survey is conducted thoroughly and is time consuming, the whole classification can be a costly operation, depending on the type of yacht and amendments that need to be made to meet the requirements.


Why do flag states require classification?

Certain yachts need to be classified, if they want to be entered in the ships registrar of a flag state. For example : in the Netherlands, yachts that are commercial exploited with a crew are subject to classification and maintained of the classification.


A maybe oversimplified recap is that classification standards of a flag state are there to regulate maritime safety and pollution prevention. Some flag states take on this responsibility very seriously and have demanding classification requirements to meet, other flag states are less concerned with such matters.


The position of the flag state in the Paris Mou White, Grey and Black List, is a rough indication on how serious a flag state considers classification.


Yacht owners’ responsibility

It goes without saying that the overall responsibility of the safety and integrity of a yacht, remains with the yacht owner. This includes the manner in which the yacht is operated and maintained.

Flag states, for example, will in most cases also have requirements with regard to the crew operating the vessel.


The definition of ‘Classification Society’

The following definition is composed by the International Association of Classification Societies.

A Classification Society is an organisation which:

  1. publishes its own classification Rules (including technical requirements) in relation to the design, construction and survey of ships , and has the capacity to (a) apply, (b) maintain and (c) update those Rules and Regulations with its own resources on a regular basis;
  2. verifies compliance with these Rules during construction and periodically during a classed ship’s service life;
  3. publishes a register of classed ships;
  4. is not controlled by, and does not have interests in, ship-owners, shipbuilders or others engaged commercially in the manufacture, equipping, repair or operation of ships; and
  5. is authorised by a Flag Administration as defined in SOLAS Chapter XI-1, Regulation 1 and listed accordingly in the IMO database, Global Integrated Shipping Information System (GISIS).


Appointed Classification Societies

Each flag state has their own classification rules. Very often the flag state has appointed a selection of classification societies to conduct the classification and the 12-monthly surveys to maintain classification.


For example in the Netherlands, the authorities have appointed the following classification societies :


It is obligatory to have the yacht classified by one of these firms. None of the other 50 classification societies are authorised to conduct classification, in the case of the Netherlands ships registrar.


In all cases it is wise to have more than one classification society make an offer, as the prices can differ dramatically. Do not focus on the costs of the initial survey alone, but also look at the costs of the periodical surveys.


Historical yachts and classification

Historical yachts and tall ships are good examples of boat types which will most probably not meet modern construction requirements and would therefore not be able to meet the required classification requirements.

Certain flag states take this into consideration and have different requirements for historical yachts and tall ships.


Ref : Classification societies – their key role, IACS