icon_arrow_down icon_arrow_left icon_arrow_left_large icon_arrow_right icon_arrow_right_large icon_arrow_up icon_bullet_arrow icon_call icon_close icon_facebook icon_googleplus icon_grid_off icon_instagram icon_login icon_mail icon_menu icon_message icon_minus icon_pinterest icon_plus icon_quote_end icon_quote_start icon_refresh icon_search icon_tick_on icon_twitter icon_video_play icon_youtube

Sign up to our mailing list for the latest Boat International & Events news.


Missing your newsletter?

If you’ve unsubscribed by mistake and would like to continue to hear about the latest Boat International & Events news, update your preferences now and let us know which emails you’d like to receive.

No, thanks
Yacht classification definitions

Yacht classification definitions

Large yachts: Applicable rules and certificates

Private yachts

The mandatory requirements for these boats are very light. For the majority of flag states, a registration survey and a tonnage measurement, carried out by an authorised surveyor, are sufficient.

The only mandatory international conventions are those relevant to the marine environment: MARPOL and the Anti-Fouling System Convention.

The International Convention for the Prevention of Pollution from Ships (MARPOL) is intended to eliminate the intentional pollution and to minimise the accidental pollution of the marine environment caused by harmful substances.

The Anti-Fouling System Convention’s purpose is to eliminate the presence of harmful substances for the marine environment contained in anti-fouling paints applied to ships.


While classification is not mandatory, building and maintaining a private yacht in class is the only evidence that the boat has been designed, constructed and operated in compliance with appropriate technical standards. It is therefore highly desirable, especially in relation to insurance and re-sale purposes.

Commercial yachts

All flag administrations require commercial yachts to be certified in accordance with a specific large yacht safety code.

The most popular of these safety codes, and the first that was developed, is the MCA Large Commercial Yacht Code (LY2) published in 2004. It replaced the Code of Practice for the Safety of Large Commercial Sailing and Motor Vessels (LY1) published in 1997.

LY2 is applied by the Red Ensign Group Flags (UK, Cayman Islands, Isle of Man, Bermuda, Gibraltar, British Virgin Islands, etc.) and is recognised as a reference standard for all the yachting industry.

Other flags have developed similar codes. Luxembourg, Italy, Marshall Islands, Malta, Belize and The Netherlands are some examples.

While introducing a stricter set of rules and regulations compared to private yachts, commercial registration offers yacht owners the possibility of making a profit from the chartering activity of their boats, and allows them to take advantage of all the other benefits of a commercial operation (in particular VAT exemption on the purchase, sale, bunkering, provisions, dry-docking, and others).

Mandatory certificates

The number and type of the mandatory certificates depends on the size of the vessel; the following is an indicative list:

  • International Tonnage Certificate : A measurement of the internal volumes of the yacht expressed in gross tons (GT). This measurement should not be confused with displacement tonnage, which quantifies the weight of a vessel.
  • Large Yacht Code Certificate : Covers life-saving appliances, fire protection and means of escape, navigational and signalling equipment, intact and damaged stability, manning and crew accommodation.
  • Class Certificate : This mainly deals with the yacht’s hull, machinery, electrical equipment and outfitting.
  • International Load Line Certificate : This certifies the weather-tightness of the yacht.
  • Safety Radio Certificate : This is applicable if gross tonnage exceeds 300GT This concerns the radio communication and distress installations.
  • MARPOL Annex I Certificate : This is applicable if gross tonnage exceeds 400GT This deals with the disposal of oil and bilge water from machinery spaces.
  • MARPOL Annex IV Certificate : This is applicable if gross tonnage exceeds 400 or the yacht is certified to carry over 15 persons. This deals with the disposal of sewage from ships.
  • MARPOL Annex V : This is applicable to all ships. It covers the disposal of rubbish.
  • MARPOL Annex VI : This is applicable if gross tonnage exceeds 400GT as well as to all main and auxiliary engines with a power exceeding 130kW. It concerns the emissions from main and auxiliary engines (NOx and SOx).
  • Safety Construction and Safety Equipment : These are additional prescriptions on machinery, electrical parts, life-saving and navigational equipment for yachts with a gross tonnage above 500GT.
  • International Safety Management Certificate : This is only applicable to yachts having a gross tonnage greater than 500GT. A certified management company is requested to carry out this service, preparing operational manuals, procedures for drills, and taking care of the maintenance of the yacht and its installations.
  • International Ship and Port Security Certificate : This is only applicable to yachts having a gross tonnage greater than 500GT and deals with the anti-piracy certification. A certified management company is requested to provide the ashore assistance and establish on-board procedures and operational manuals.
Upgrade your account
Your account at BOAT International doesn't include a BOAT Pro subscription. Please subscribe to BOAT Pro in order to unlock this content.
Subscribe More about BOAT Pro