Quick Reference Guide



Legislation :Code for the Construction and Equipment of Mobile Offshore Drilling Units, 1979 (MODU Code), adopted by Resolution A.414(XI) on 15 November 1979 or for units constructed on or after 1 May 1991, the Code for the Construction and Equipment of Mobile Offshore Drilling Units, 1989 (MODU Code), adopted by Resolution A.649(16) on 19 October 1989 and modified by Resolution MSC;38(63) on 19 May 1994.

Application :offshore drilling units as defined in Paragraphs 1.3.1 to 1.3.4 : mobile offshore drilling units, surface units, Self-elevating units and column-stabilized units (MODU Code, Chapter 1, Paragraph 1.2.1).

Duration and validity :maximum 5 years (MODU Code, Chapter 1, Paragraph

The Certificate shall cease to be valid:

if the relevant surveys are not completed within the periods specified in Par. 1.6.1 (MODU Code, Chapter 1, Paragraph

if the Certificate is not endorsed in accordance with Par 1.6.3 (MODU Code, Chapter 1, Paragraph

upon transfer of the ship to the flag of another State (MODU Code, Chapter 1, Paragraph

Extension :exceptionally, when at the time of expiration of the certificate the ship is not in the place in which it is to be surveyed, the Administration may extend the period of validity for maximum 3 months to allow the ship to complete its voyage and only in cases it appears reasonable to do so (MODU Code, Chapter 1, Paragraph

Surveys :an initial survey before the unit is put in service or before the Certificate is issued for the first time (MODU Code, Chapter 1, Paragraph

renewal survey not exceeding 5 years, except where Par or or is applicable (MODU Code, Chapter 1, Paragraph

an intermediate survey, within 3 months before or after the second anniversary date or within three months before or after the third anniversary date of the Certificate, which should take the place of one of the annual surveys (MODU Code, Chapter 1, Paragraph

an annual survey within three months before or after each anniversary date of the Certificate (MODU Code, Chapter 1, Paragraph

minimum of two dry dock surveys during any five year period, except where Par. is applicable. Where Par. is applicable this five year period may extend to coincide with the extended period of the validity of the Certificate. In all cases the intervals between any two such surveys should not exceed 36 months (MODU Code, Chapter 1, Paragraph

radio station surveys in accordance with Par. 11.10 (MODU Code, Chapter 1, Paragraph

an additional survey as the occasion arises (MODU Code, Chapter 1, Paragraph

Request :Owner or shipbuilder to the Administration (e.g. the Maritime Inspectorate) or to an authorized Organization (e.g. a classification society).

Issue :Administration or authorized Organization (MODU Code, Chapter 1, Paragraph 1.6.7).

Inspections and Surveys :Administration or authorized Organization (MODU Code, Chapter 1, Paragraph

Endorsements :the intermediate, annual and dry dock surveys should be endorsed on the Certificate (MODU Code, Chapter 1, Paragraph 1.6.3).


  • As an alternative to the renewal and intermediate surveys, the Administration may, at the owner's request, approve a continuous survey programme provided that the extent and frequency of the surveys are equivalent to renewal and intermediate surveys. A copy of the continuous survey programme, together with the record of the surveys, should be kept on board the unit and the Certificate annotated accordingly (MODU Code, Chapter 1, Paragraph 1.6.4).
  • The requirements regarding surveys and certification are without prejudice to any rights of the coastal State under international law to impose its own requirements relating to the regulation, surveying and inspection on units engaged, or intending to engage, in the exploration or exploitation of the natural resources of those parts of the sea-bed and subsoil over which that State is entitled to exercise sovereign rights (MODU Code, Chapter 1, Paragraph 1.7.6).