Remote sensing is usually understood by the Earth observation sector to be looking down from aircraft or satellites. A new partnership between the Nippon Foundation-GEBCO Seabed 2030 Project and ocean technology company Ulysses, is a reminder that some of the planet’s most important remote observations are made looking down through water.
Announced on 27 July 2026, the partnership will explore how Ulysses’ autonomous surface and underwater systems can support the collection and sharing of bathymetric data. The intended destination is the free, publicly available GEBCO global grid, which Seabed 2030 is working to complete for the entire ocean floor.
This matters well beyond hydrography. Better bathymetry supports safer navigation, tsunami modelling, marine habitat assessment, ocean circulation research, offshore infrastructure and the responsible management of marine resources. It also illustrates an increasingly important commercial model for Earth observation: combine different sensing domains, reduce collection costs with autonomy and treat open foundational data as infrastructure on which higher-value services can be built.
What is bathymetry?
Bathymetry is the measurement and representation of the depth and shape of the seabed beneath oceans, seas, rivers and lakes. It is the underwater counterpart of topography. A bathymetric dataset can be turned into depth contours, terrain models and three-dimensional representations of features such as continental shelves, canyons, ridges, seamounts and trenches.
The simplest historical method was a weighted line lowered from a vessel. Modern surveys predominantly use acoustic systems. A single-beam echo sounder measures depth beneath a vessel from the travel time of a sound pulse, while a multibeam echo sounder transmits a fan of sound to collect a swath of measurements across the seabed. The result is a detailed three-dimensional model rather than a single line of depths.
Airborne bathymetric lidar offers another form of remote measurement in clear, shallow water. It compares the returns from an infrared laser pulse reflected by the water surface and a green pulse capable of penetrating the water column. According to the US National Oceanic and Atmospheric Administration, suitable systems can reach depths of around 50 metres in good water clarity, making lidar useful around coastlines where vessels may be constrained by rocks, surf or other hazards.
Satellites contribute differently. Radar altimeters measure very small variations in sea-surface height. Large seabed features alter the local gravity field and produce subtle changes in the shape of the ocean surface, allowing scientists to infer broad underwater topography. This provides global context but not the accuracy or detail of direct echo sounding. The strongest global bathymetric models therefore combine satellite-derived estimates with acoustic measurements, lidar and other contributed data.
Why so much of the seabed remains poorly mapped
Water prevents ordinary optical and radar instruments from directly observing most of the deep ocean floor. High-resolution mapping requires a sensor to travel over the area, generally on a ship or an uncrewed platform, and survey a series of swaths. The ocean is vast, survey vessels are expensive and remote waters can be difficult to reach.
Seabed 2030 reported in April 2026 that 28.7% of the world’s ocean floor had been mapped to modern standards. That represents approximately 104 million square kilometres and an increase of almost five million square kilometres in a year. It is substantial progress from the 6% available when the project began, but it also means more than seven-tenths of the seabed still lacks modern mapped coverage.
Not every gap must be filled by a newly commissioned expedition. Valuable measurements already exist in the archives of governments, research institutes and commercial operators. Vessels can also contribute measurements collected while carrying out routine work. The challenge is therefore partly one of new acquisition and partly one of finding, quality-checking and releasing data that has already been collected.
GEBCO: a global map built through cooperation
The General Bathymetric Chart of the Oceans, or GEBCO, operates under the joint auspices of the International Hydrographic Organization and UNESCO’s Intergovernmental Oceanographic Commission. Its aim is to produce free, open and complete seabed data and information for the world’s oceans.
GEBCO traces its history to 1903. Today it produces global gridded bathymetric datasets, web services, maps, a gazetteer of undersea feature names and technical guidance for creating bathymetric grids. Its work depends heavily on international collaboration and voluntary contributions from hydrographers, geoscientists, governments, researchers and industry.
The Nippon Foundation-GEBCO Seabed 2030 Project was established to accelerate that work and create the definitive high-resolution map of the entire ocean floor by 2030. It gathers data through regional centres, helps identify priority gaps and incorporates suitable contributions into the GEBCO Ocean Map. The project is recognised as an action of the United Nations Decade of Ocean Science for Sustainable Development.
The 2030 date is highly ambitious given the remaining area. The enduring value of the initiative, however, does not depend solely on meeting a single deadline. It is creating shared standards, relationships, data pipelines and expectations of openness that can improve the global ocean map with every new contribution.
The social innovation behind The Nippon Foundation
The Nippon Foundation is a private, non-profit foundation based in Japan. Its description of social innovation is reflected in a model that connects people and organisations around problems that no single institution can solve. In its ocean work, it emphasises both technology and the human capacity needed to use it.
Its relationship with GEBCO predates Seabed 2030. Since 2004, the Foundation has supported postgraduate training in ocean bathymetry at the University of New Hampshire, helping to develop an international network of ocean mappers. This capacity-building dimension is important: a global dataset requires trained people, trusted institutions and cooperation across national boundaries as much as it requires sensors.
Seabed 2030 applies the same philosophy at scale. Governments, universities, hydrographic offices, companies and individuals can all contribute to a common public resource. The benefit is social as well as scientific. Better knowledge of the seabed can support coastal communities, disaster preparedness, environmental protection, communications infrastructure and safer use of the ocean.
What Ulysses brings to the partnership
Founded in 2023, Ulysses develops networked autonomous surface and underwater vehicles for applications including environmental monitoring, habitat restoration and seabed mapping. Its systems combine sensing, robotics, onboard computing and modular payloads.
The attraction for ocean mapping is scale and persistence. Autonomous platforms can potentially operate without the cost and risk of keeping a large crewed vessel continuously over the survey area. Fleets can gather measurements across wider areas, revisit locations and support missions in waters that are difficult or uneconomic to survey conventionally.
Those advantages should not be exaggerated. The announcement does not specify a deployment, survey area or volume of data. It says the partners will explore opportunities to support bathymetric data collection and sharing. Autonomous operations must still deal with endurance, navigation, communications, weather, sensor calibration, data quality and regulatory requirements.
The importance of the partnership is therefore not that it completes the map by itself. It provides a route by which a commercial technology developer can align future collection with an established global data framework, increasing the chance that observations gathered for individual missions also create wider public value.
A wider Earth observation opportunity
Bathymetry sits naturally within a wider observation system. Satellite altimetry provides broad indications of deep-ocean structure. Optical satellite imagery can support satellite-derived bathymetry in suitably clear, shallow waters. Airborne lidar can bridge the land-water boundary, while sonar from ships and autonomous platforms supplies the direct, higher-resolution depth measurements needed below the surface.
Combining these sources creates commercial opportunities in data fusion, mission planning, quality assurance, change detection, coastal risk, offshore energy, cable routing, habitat mapping and digital twins of the ocean. EO companies do not need to become vehicle manufacturers to participate. Their expertise in geospatial processing, uncertainty, scalable data platforms and turning measurements into decisions is directly relevant.
Open foundational data should not be confused with an absence of commercial value. A trusted global grid can reduce duplication and give businesses a common reference layer. Revenue can then come from fresher or higher-resolution surveys, specialised analysis, operational monitoring, risk models and decision-ready services.
The constructive lesson from the Seabed 2030-Ulysses partnership is that observation markets grow when technology, people and data governance develop together. Autonomous systems may make collection more scalable, but their greatest impact will come when the resulting measurements are interoperable, trusted and connected to users. That principle is as relevant above the ocean as it is beneath it.
Read the Seabed 2030 and Ulysses partnership announcement.