Understanding The Underwater World With Hydrographic Surveying

Beneath the shimmering allure of Earth’s expansive water bodies lies a captivating realm waiting to be discovered through the fascinating field of hydrographic surveying. This scientific pursuit involves meticulous measurements and descriptions of the physical features of the underwater environment, including soundings, shorelines, tides, currents, seabed composition, and submerged obstacles. Through these efforts, hydrographic surveyors unveil the intricate tapestry of the ocean floor, shedding light on its hidden wonders.

In the past, coastal development faced unforeseen challenges due to the absence of these surveys. However, today, hydrographic surveys have become indispensable from the very inception of projects. They ensure precise design decisions, resulting in structures that are accessible and require minimal maintenance. With over 70% of our planet covered by water, understanding the dimensions of the seabed becomes paramount. Hydrographic surveys, also known as underwater explorations, provide invaluable insights into the contortions and elevations of the ocean floor. This knowledge enables safe navigation, informed decision-making, and the sustainable exploration of our vast marine resources.

Embark on an illuminating journey as we delve into the realm of hydrographic surveying, unraveling its purpose and methods that shape our relationship with the mesmerizing aquatic wonders of the world.

kd perantau hydro

KD Perantau hydrography ship (Secure Malaysia)


Hydrographic survey is of paramount importance across various aspects of maritime activities and coastal management. This field addresses the challenges posed by the complex underwater environment, enabling us to overcome obstacles and harness the opportunities it presents. Let’s explore in detail the key reasons that underscore the significance of hydrographic survey:

  1. Navigational safety: Hydrographic surveys provide accurate and up-to-date data for safe navigation, especially in areas with complex water depths and shifting seabed conditions. Empowering mariners with invaluable information, these surveys enable precise nautical charting and digital navigation systems, ensuring a confident voyage while avoiding potential dangers. The International Hydrographic Organization (IHO) places utmost importance on hydrographic surveys to safeguard navigational safety.

  2. Marine construction and infrastructure development: In marine construction projects, hydrographic surveys offer comprehensive insights into water depths, seabed conditions, and potential obstructions. This information facilitates strategic infrastructure planning, taking environmental factors into account and minimizing risks. The United Nations Convention on the Law of the Sea (UNCLOS) recognizes the indispensable nature of hydrographic surveys for the construction of artificial islands and offshore installations.

  3. Dredging operations: Hydrographic surveys play a critical role in identifying areas that require dredging, assessing sediment accumulation, and monitoring dredging effectiveness. Precise bathymetric data obtained through these surveys optimizes dredging activities, promotes safe navigation, and aids in coastal erosion management, ensuring navigable waterways and sustainable land reclamation. The International Association of Dredging Companies (IADC) acknowledges the pivotal role of hydrographic surveys in dredging operations.

  4. Environmental management and conservation: Hydrographic surveys contribute significantly to environmental management and conservation. By providing valuable information about seabed composition, habitat mapping, and biodiversity assessments, these surveys aid in identifying ecologically sensitive areas and supporting the establishment of marine protected areas.  The International Union for Conservation of Nature (IUCN) recognizes hydrographic surveys as a powerful tool for marine spatial planning and conservation initiatives.

By recognizing the multifaceted importance of hydrographic surveys, we can appreciate their role in ensuring navigational safety, facilitating marine construction, optimizing dredging operations, and promoting environmental management and conservation. Join us as we delve deeper into the fascinating world of hydrographic surveys, uncovering their methodologies and exploring their wide-ranging applications.


The method of hydrographic surveying varies based on factors such as project type, scale, available resources, and technology, as well as quality and accuracy requirements. In essence, hydrographic surveying encompasses three key steps: data acquisition, data processing, and data application.

Data Acquisition

Hydrographic surveying involves collecting data on the underwater environment using a range of instruments and sensors. These tools are mounted on platforms like ships, boats, aircraft, satellites, buoys, or autonomous vehicles. Common instruments include:

  • Echo Sounders: These devices emit sound pulses into the water and calculate depth and position by measuring the time it takes for the pulses to bounce back from the seabed or objects. Echo sounders are essential for obtaining bathymetric data, which reveals water depths and the shape of the seabed.
  • Sonars: Sonars use sound waves to scan and image large areas underwater. Active sonars emit sound waves and receive echoes, while passive sonars listen to sound waves from other sources. Sonars provide detailed images of seabed features and objects, helping to identify potential hazards or submerged structures.
  • LiDAR: LiDAR use laser beams to measure distances and elevations of the water surface or objects. They provide accurate information on water level changes, as well as the height and shape of structures along the coast. Lidar data is particularly useful for coastal zone management and monitoring shoreline erosion.
  • Cameras: Underwater cameras capture optical images or videos using visible light or other wavelengths. They provide valuable information on the seabed’s color, texture, composition, and marine life. By visualizing the underwater environment, cameras aid in habitat mapping and assessing the ecological health of marine ecosystems.
Data Processing

After data acquisition, the raw data is processed to transform it into meaningful information for analysis. This involves several steps:

  • Data Validation: Checking and correcting errors or inconsistencies caused by noise, interference, or instrument malfunction. Calibration and quality control measures are crucial to ensuring data accuracy.
  • Data Integration: Combining data from different sources or platforms into a common reference system. The integration allows for a comprehensive view of the underwater environment, incorporating data from various instruments and surveys.
  • Data Enhancement: Improving data quality or resolution through techniques like filtering, smoothing, interpolation, or extrapolation. Enhancing the data ensures that the final output is reliable and useful for decision-making.
  • Data Visualization: Creating graphical representations of the data using maps, charts, graphs, images, animations, or interactive displays. Visualization helps to communicate complex information in a more accessible and intuitive manner.
Data Application

Processed data is then utilized for various purposes:

  • Data Analysis: Examining and interpreting data using statistical methods, modeling, simulation, or machine learning. The analysis allows surveyors and scientists to extract meaningful insights from the collected data, uncovering patterns, trends, and relationships.
  • Data Dissemination: Sharing data with government agencies, private companies, academic institutions, or the public. Dissemination of hydrographic data fosters collaboration, research, and informed decision-making in various sectors, including navigation, coastal management, and marine resource exploration.
  • Data Storage: Preserving data for future use through archiving, backup, or cloud services. Storing data ensures that it remains accessible and can be revisited for historical analysis or comparisons.


Hydrographic surveying is an engaging field that offers exciting opportunities to explore and comprehend the underwater realm. It plays a crucial role in sustainable development and the effective management of our vital water resources, ensuring the well-being and prosperity of humanity.

As indicated by a survey conducted by Hydro International, the hydrographic industry is poised for continued growth and demand in 2023. However, it also faces significant challenges in the coming years. These challenges include attracting and training a new generation of surveyors, adapting to emerging technologies like autonomy and AI, enhancing training and competency development, and enabling the utilization of survey data for diverse purposes.

Fortunately, the field of hydrographic surveying is advancing rapidly, with innovative solutions and technological breakthroughs paving the way. Multibeam sonar systems, airborne lidar bathymetry, unmanned survey platforms, and advanced data processing techniques have revolutionized surveying practices, ensuring greater accuracy, efficiency, and environmental consciousness. Through ongoing developments and a commitment to overcoming challenges, hydrographic surveying continues to lead the way in unraveling the mysteries of the underwater world while supporting maritime activities and environmental stewardship.

Image by INFOMAR


  • Communicatie, F. M. &. (n.d.). Importance of hydrography. International Hydrographic Organization. https://iho.int/en/importance-of-hydrography
  • U.S. Department of Commerce. (n.d.). Hydrographic surveys specifications and Deliverables. National Oceanic and Atmospheric Administration. https://nauticalcharts.noaa.gov/publications/docs/standards-and-requirements/specs/hssd-2017.pdf
  • US Department of Commerce, N. O. and A. A. (2013, June 1). What is hydrography?. NOAA’s National Ocean Service. https://oceanservice.noaa.gov/facts/hydrography.html#:~:text=NOAA’s%20Office%20of%20Coast%20Survey,ocean%20and%20our%20nation’s%20waterways
  • Wegen, W. van. (2022, December 3). New horizons for hydrography, but who will conquer them?. Hydro International. https://www.hydro-international.com/content/article/new-horizons-for-hydrography-but-who-will-conquer-them


Sign up to receive email updates on new product announcement, case study, special promotion, sales and more.

Copyright © 2023           Designed and developed by OFO Tech