The Role of Ηydrography

On 21st June each year the International Hydrographic Organization celebrates World Hydrography Day. Hydrography Day is an opportunity to increase public awareness of the vital role that Hydrography plays in everyone’s life.

The theme for this year’s World Hydrography Day is: “Hydrography – underpinning the blue economy”.

Hydrography and “Blue Economy”

The term “blue economy” means… the sum of all economic activity associated with the oceans, seas, harbors, ports, and coastal zones. The seas and oceans are major contributors to the world economy. They occupy 71% of the world’s surface area and over 90% of the world’s trade travels by sea and ,including the seabed and the sub-seabed, represent a vast resource for food, mineral resources, energy, water, bio-medicines, and infrastructure that in turn creates wealth for individuals and for nations.The exploitation of water resources and the development of activities related to the Sea offers many employment opportunities as it contributes to the development of a country’s overall economy.

In addition to supporting safe and efficient navigation of ships, Hydrography underpins almost every other activity associated with the sea, including:

• resource exploitation – fishing, minerals

• environmental protection and management

• maritime boundary delimitation

• national marine spatial data infrastructures

• recreational boating

• maritime defence and security

• tsunami flood and inundation modelling

• coastal zone management

• tourism

• marine science

Despite the importance of this economic theory, there is lack of hydrographic data and only 10% of the seas have been studied systematically. This need for better knowledge of the seas and the oceans shows the importance of Hydrographic surveyors.

Role of Hydrographic Surveyors and Nautical Cartographers

Hydrographic surveyors work in both the public and private sector. Government hydrographic surveyors are usually involved in surveying to improve nautical charts and provide qualified base data for maritime geospatial information systems. Commercial hydrographic surveyors are often involved in specialized tasks including surveys for undersea pipelines and cables, the installation of offshore structures including wind farms, oil and gas platforms and surveys for new ports and harbours. They also survey under contract to improve charts.


Hydrographic surveyors use echo sounders, high definition sonars in boats and ships, lasers from aircraft and sometimes satellite images to obtain precise and accurate measurements of depth. They also need to be experts in precise positioning and in the measurement of currents and tides.


Nautical cartographers take information from hydrographic surveys and from other sources and turn it into nautical charts and other marine geospatial products and services. Traditionally, the charts are printed on paper but increasingly now they are made in the form of digital electronic charts, as well. The charts use international standards set by the IHO to ensure that they can be used and understood by all mariners – from anywhere in the world.

Role of the IHO

The principal role of the IHO, as the competent international authority for Hydrography, nautical charting and associated matters, is to improve the provision of adequate and timely hydrographic data, products and services to all parts of the world. This directly supports the Blue Economy. The role includes the maintenance of international standards to help ensure that mariners and other users of hydrographic data can use and understand the data easily.