Offshore Development Areas

  • Operations notice: 42
  • Issue date: Jan 2002


1. This notice gives details of the arrangements for the creation of offshore development areas (ODAs).


2. Offshore development areas were introduced in 1980 as a means of advising mariners not to enter particular areas because of the high levels of activity associated with the establishment of offshore installations. HSE acts as a link between operators, consultees and the Hydrographic Office.

3. ODAs have no statutory force and are advisory only, but have been used to supplement statutory 500 metre safety zones.


4. Application to establish an offshore development area may be made to HSE who will act as the link between interested parties. After consultation ODAs will be marked on Admiralty charts, and a Notice to Mariners issued by the Hydrographer.

  1. applications for ODAs should be submitted only for the initial construction phase of a development. ODA status will therefore be granted for a specific period of time, and operators will need to specify the length of time they require when applying for ODA status;
  2. prior to the completion of the initial construction phase of a development, where it is felt that sub-sea installations require appropriate designation on charts consistent with section 21 of the Petroleum Act 1987 to protect the health and safety of workers, operators should consider applying to HSE for an offshore safety zone.

5. If operators feel specific markings are necessary for circumstances other than in paragraph 3, they should apply to the Hydrographic Office to have a revised warning note included on Admiralty charts for the information of all mariners including fishermen.

6. In all cases, the Hydrographic Office has advised that they must be provided with full details of all activities/installations so that a decision can be made on the most appropriate way in which this information is distributed, to ensure the safety of all categories of mariners. Any such action would be entirely a matter for operators and mariners, and would not involve HSE.

7. The Hydrographic Office is situated at:

Hydrographic Office
Admiralty Way

Tel: 01823 337900

Further information

8. Any queries relating to this notice should be addressed to:

Health and Safety Executive
Hazardous Installations Directorate
Offshore Division
Lord Cullen House
Fraser Place
AB25 3UB

This guidance is issued by the Health and Safety Executive. Following the guidance is not compulsory and you are free to take other action. But if you do follow the guidance you will normally be doing enough to comply with the law. Health and safety inspectors seek to secure compliance with the law and may refer to this guidance as illustrating good practice

Updated 2021-02-16