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World Hydrography Day is celebrated on June 21 every year, since 2005. It is celebrated to raise awareness of the importance of hydrography and to publicise the work of hydrographers all around the world. Hydrography is the science that measures and describes the physical features of the navigable portion of the Earth’s surface and adjoining coastal areas.International Hydrographic Organization (IHO) proposed World Hydrography Day in the United Nations. World Hydrography Day is an opportunity for hydrographers around the globe to highlight the significance and importance of their activities. Also hydrographers based on data received suggests initiatives that support the safety of navigation, the protection of the marine environment, coastal zone management, marine spatial data infrastructures, defence and security, resource exploration, and all other components of the blue economy. In this article we will check the significance, theme and history of World Hydrography Day
World Hydrography Day 2025 Date – June 21
In this article readers can get a glimpse on
- History and Significance of World Hydrography Day
- World Hydrography Day Theme 2025
- World Hydrography Day Quiz
Hydrography and it’s Significance
1: Who was the first woman President of India?
Hydrography is the branch of applied sciences which deals with the measurement and description of the physical features of oceans, seas, coastal areas, lakes and rivers, as well as with the prediction of their change over time. The important factor of hydrography is to provide safety of navigation and in support of all other marine activities, including economic development, security and defense, scientific research, and environmental protection of country.
Hydrographer measures and searches for rocks and wrecks that could be hazardous to navigation. They also collect information on water levels, tides, currents, temperature and salinity. Hydrographers conduct hydrographic surveys to measure the depth and bottom configuration of water bodies. The data’s received from these surveys are used to update nautical charts and develop hydrographic models. The information gained from these is vital on safer navigation in the ocean and to understand our nation’s waterways.
Other Important benefits of Hydrography is as follows-
– Resource exploitation – fishing, minerals
– Environmental protection and management
– Maritime boundary delimitation
– National marine spatial data infrastructures
– Recreational boating
– Maritime defense and security
– Tsunami flood and inundation modeling
– Coastal zone management
– Tourism
– Marine science
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Start Learning!How Hydrography is carried out?
Hydrographers conduct hydrographic surveys to measure the depth and bottom configuration of water bodies. This is done mainly with specialized ships and boats with echo sounders and sonars. Also they use survey aircraft fitted with lasers and data can be derived from satellite observations which helps in monitoring tides and currents.
History of World Hydrography Day
The International Hydrographic Bureau was established in 1921, for the purpose of providing a mechanism for consultation between governments on matters such as technical standards, safe navigation and the protection of the marine environment. Which later in 1970, changed it’s name to International Hydrographic Organization (IHO).
IHO first proposed the concept of a World Hydrography Day in 2005 at United Nations General Assembly. This idea got acceptance from the United Nations General Assembly in Resolution A/RES/60/30 Oceans and the law of the sea with the aim of giving publicity to its work at all level and of increasing the coverage of hydrographic information on a global basis. Also urged all States around globe to work with IHO to promote safe navigation, especially in the areas of international navigation, ports and where there are vulnerable or protected marine areas. The first World Hydrography Day was celebrated in 2006.
World Hydrography Day Theme 2025
The theme for World Hydrography Day 2025, “Seabed Mapping: Enabling Ocean Action,” emphasizes the essential role of detailed and accurate seabed data in supporting global ocean initiatives. Mapping the ocean floor provides the foundation for understanding marine ecosystems, improving navigational safety, and addressing climate-related challenges. With much of the ocean still unexplored, seabed mapping helps reveal underwater features critical for biodiversity conservation, marine spatial planning, and disaster risk reduction.
This year’s theme highlights the importance of hydrography in advancing the goals of the UN Decade of Ocean Science for Sustainable Development (2021–2030). By gathering data on ocean depths, underwater terrain, and seafloor composition, hydrographic surveys contribute directly to scientific research, environmental monitoring, and responsible ocean governance. The International Hydrographic Organization (IHO) continues to lead global efforts in expanding access to high-quality seabed data, ensuring that informed actions can be taken to protect our oceans for future generations.
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Start Learning!World Hydrography Day Previous Themes
World Hydrography Day, observed annually on June 21, was established by the International Hydrographic Organization (IHO) and later welcomed by the United Nations General Assembly in 2005. It aims to raise awareness about the vital role of hydrography in safe navigation, environmental protection, and sustainable use of the oceans, seas, and waterways. The date commemorates the founding of the IHO in 1921.
Each year, a specific theme is chosen by the IHO to highlight different aspects of hydrography. Here are the themes from recent years:
- 2007: Electronic Navigational Charts (ENCs); an essential element of safety at sea and efficient maritime operations.
- 2008: Capacity Building, a vital tool to assist the IHO in achieving its mission and objectives.
- 2009: Hydrography – Protecting the marine environment.
- 2010: Hydrographic Services – the essential element for maritime trade.
- 2011: Human Resources – The important element to the success of hydrography.
- 2012: International Hydrographic Cooperation – supporting safe navigation.
- 2013: Hydrography – underpinning the Blue Economy.
- 2014: Hydrography – much more than just nautical charts.
- 2015: Our seas and waterways – yet to be fully charted and explored.
- 2016: Hydrography – the key to well-managed seas and waterways.
- 2017: Mapping our seas, oceans and waterways – more important than ever.
- 2018: Bathymetry – the foundation for sustainable seas, oceans and waterways.
- 2019: Hydrographic information driving marine knowledge.
- 2020: Hydrography enabling autonomous technologies.
- 2021: 100 years of international cooperation in hydrography.
- 2022: Hydrography – contributing to the United Nations Ocean Decade.
- 2023: Hydrography – underpinning the digital twin of the ocean.
- 2024: Hydrographic Information – Enhancing Safety, Efficiency and Sustainability in Marine Activities.
How World Hydrography Day is celebrated?
World Hydrography Day is celebrated based on the theme selected, which is selected by the Member States of the International Hydrographic Organization (IHO). Based on the theme, IHO develops wide range of activities. Such as-
- Awards
- Conferences
- Seminars
- Workshops
- Lectures
- Dinners
- Public events
- Demonstrations
- Promotional material
Also the IHO Secretariat will post Member State and stakeholder initiatives on the dedicated page on the IHO website and/or social media outlets. Alternatively, contributors are invited to post on their own social media outlets and tag the IHO. Suggested hashtags include #WorldHydrographyDay and #WHD.
World Hydrography Day- Messages
- With the increasing population, we all need to stay alert, and on this extraordinary day, let’s take an initiative that would help us conserve our marine resources.
- Hope we all can take out some time from our busy schedule and plan out something to protect our mother Earth’s marine resources on this great day.
- This day is celebrated to acknowledge the work of IHO and to spread the importance of hydrography.
- It’s us who can save Earth’s resources. Let us contribute to this cause by celebrating this great day.
- feel it’s us who can play a very crucial role in this hydrography day to conserve our marine resources. We all need to take a moment out to help each worker of the organization and acknowledge their work.
World Hydrography Day Quiz 2025
A) IMO
B) WMO
C) IHO
3. Where is the IHO headquarters located?
A) Geneva
B) New York
C) Monaco
A) Weather forecasting
B) Ocean and seabed mapping
C) Desert studies
5. What is bathymetry the study of?
A) Rainfall
B) Ocean depth
C) Wind speed
A) Radar
B) Sonar
C) Barometer
A) Road maps
B) Climate charts
C) Nautical charts
A) Monthly
B) Annually
C) Every five years
B) Hydrographer
C) Meteorologist
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World Hydrography Day Quiz 2025 PDF
World Hydrography Day serves as a powerful reminder of the vital role that hydrography plays in ensuring safe navigation, protecting marine environments, and supporting sustainable ocean development. From creating nautical charts to enabling emergency response and coastal zone management, hydrographic data supports a wide range of critical activities. As our oceans face increasing pressures from climate change, pollution, and overuse, the importance of accurate seabed mapping and ocean observation continues to grow.
By celebrating World Hydrography Day, we acknowledge the ongoing efforts of hydrographers and maritime organizations working tirelessly to explore and understand our oceans. The 2025 theme reinforces the urgency of seabed mapping in enabling ocean action and contributing to global marine goals. Increased international cooperation, technological innovation, and public awareness are key to unlocking the full potential of our oceans while safeguarding them for the future.`
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Start Learning!Frequently Asked Questions
What is World Hydrography Day and why is it celebrated?
World Hydrography Day is observed annually on June 21 to recognize the work of hydrographers and the importance of hydrography. It was established by the International Hydrographic Organization (IHO) in 2005. The day promotes awareness about the science of mapping the seafloor and measuring ocean characteristics. These efforts are essential for safe navigation, marine conservation, and disaster prevention. The celebration also highlights technological advancements and encourages global cooperation in ocean-related data collection.
What is hydrography and how is it different from oceanography?
Hydrography is the science of measuring and describing the physical features of oceans, seas, lakes, and rivers. It primarily supports navigation, marine infrastructure, and coastal management. Oceanography is a broader field that studies all aspects of oceans including biology, chemistry, and climate. While both fields may overlap, hydrography focuses on mapping and safety-related data. Hydrographic surveys are mainly used for nautical charts and maritime safety systems.
Who conducts hydrographic surveys and what tools do they use?
Hydrographic surveys are conducted by trained professionals called hydrographers. These surveys are usually carried out using specialized ships, boats, or remotely operated vehicles. Tools like echo sounders, sonars, GPS systems, and satellite imagery are commonly used. Data is processed using Geographic Information Systems (GIS) to create charts and maps. National hydrographic offices and naval organizations often lead these efforts.
Why is seabed mapping so important for ocean conservation?
Seabed mapping reveals the topography and features of the ocean floor, such as trenches, ridges, and habitats. This information is critical for identifying ecologically sensitive areas and planning marine protected zones. It also helps in detecting environmental threats like underwater pollution and habitat loss. Accurate maps guide policy decisions that support marine biodiversity. Overall, seabed data is a foundation for sustainable ocean management.
How does hydrography contribute to maritime safety?
Hydrography provides precise information on water depths, seafloor hazards, tides, and currents. This data is used to produce nautical charts that guide ships safely through ports and waterways. It helps avoid accidents such as groundings and collisions. Real-time updates from hydrographic surveys also support dynamic navigation systems. Without hydrography, maritime transport would be far more risky and inefficient.
What role does the International Hydrographic Organization (IHO) play?
The IHO is an intergovernmental organization based in Monaco that leads global efforts in hydrography. It sets standards for hydrographic data collection, charting, and information exchange. The IHO also supports member states in developing technical capabilities and sharing ocean data. It launched World Hydrography Day to raise awareness about hydrography’s importance. The organization plays a central role in coordinating global seabed mapping initiatives.
What are nautical charts and how are they used?
Nautical charts are maps specifically designed for maritime navigation. They show water depths, seafloor features, navigation aids, hazards, and coastline shapes. Ships rely on these charts to plan safe routes and avoid dangers. Charts can be paper-based or digital, with frequent updates from hydrographic surveys. They are essential tools for commercial shipping, naval operations, and recreational boating.
How can seabed mapping support climate change response?
Seabed mapping provides data on underwater terrain that helps model ocean currents and sea-level rise. It supports the identification of carbon storage zones such as seagrass beds and mangroves. Mapping also reveals coastal erosion patterns and areas at risk of storm surges. This information aids in designing climate-resilient infrastructure and emergency plans. In short, seabed data informs long-term strategies for climate adaptation and mitigation.
How can individuals and students learn more or contribute to hydrography?
Individuals can explore resources from organizations like the IHO and national hydrographic offices. Educational programs in marine science, oceanography, and geospatial technology often include hydrography. Students can participate in internships, field surveys, or citizen science projects involving coastal mapping. Public awareness campaigns and online webinars are also great learning opportunities. Supporting sustainable ocean actions and staying informed about ocean science contributes to the global hydrography mission.
What are some real-world applications of hydrographic data beyond navigation?
Hydrographic data is used in many fields beyond maritime navigation. It supports offshore wind farm planning by providing detailed seabed conditions. Coastal engineers use it to design ports, bridges, and flood defenses. Environmental scientists rely on this data to monitor marine habitats and pollution. It also aids in disaster response, such as tsunami modeling and oil spill containment.
