The RHCs complement the work of the International Hydrographic Organization (IHO) through the regional co-ordination of nautical information, hydrographic surveys, production of nautical charts and documents, training, and technical co-operation and hydrographic capacity building projects to be co-ordinated within each region. The RHCs are an important way of facilitating the exchange of information and consultation between hydrographic services, particularly those that are not presently members of the IHO. Geographically adjacent RHCs also liase with each other.

Co-ordination
The NAVAREA regions jointly established by the IHO, International Maritime Organization (IMO) and World Meteorological Organization (WMO) for the dissemination of maritime safety information (MSI) have been closely aligned with the RHCs for the obvious reason of better co-ordination. For the same reason, the co-ordination of both INT paper charts and electronic navigational chart (ENC) production is also based primarily on RHC areas.

Members
The RHCs are made up of IHO Member States within each region as full members, together with associate members and observers. Representatives of the IHO Secretariat are assigned to each RHC and are invited to attend the meetings. One of the IHOs three directors is assigned to each RHC. Hydrographic and maritime industry representatives attend RHC meetings. Each RHC is represented on the IHO Inter Regional Coordination Committee (IRCC) by its elected chair. The IRCC meets annually and is the forum where regional hydrographic and charting issues are discussed and co-ordinated at the global level.

Meetings
At the RHC meetings, members report and share experiences on their organisation, hydrographic and cartographic programmes, new technologies and/or equipment incorporated in their processes. Other subjects considered are, for instance, bilateral, multilateral or regional development projects with hydrographic components. In its Assembly Resolution 58/240, the UN encouraged an increase in mem-bership of the IHO. RHCs play an important role in following this up. They provide the opportunity for maritime nations who are not yet IHO members to establish practical links with the IHO and its technical and co-ordination bodies. Details of each RHC can be found on the IHO website (website 1).

The fourteen regional hydrographic commissions and the hydrographic commission on Antarctica