Expanded Global Seafloor Mapping: The Case for a Comprehensive Bathymetric Chart Beyond the Scope of the General Bathymetric Chart of the Oceans (GEBCO)
The production of Bathymetric Charts, crucial for both scientific and economic purposes, is a costly business, funded primarily from national resources with limited re-balance from chart sales. The most efficient publishers of these charts are the Hydrographic Offices, responsible for producing and publishing small-scale navigational charts.
One of the most well-known series of Bathymetric Charts is the GEBCO series, produced by the International Hydrographic Bureau (IHB) in collaboration with member states of the International Hydrographic Organization (IHO). The GEBCO series, comprising 16 buttjoining sheets each covering 90° of Longitude, provides a world-wide Bathymetric Chart on a scale larger than most.
The GEBCO series shows bathymetric contours at every 1 000 metres outside the Continental Shelf and Margins. However, despite being the only world-wide Bathymetric Chart at present, its resolution is still considered coarse for many applications. GEBCO provides coverage primarily at a resolution of about 15 arc-seconds, which is roughly 450 meters grid cells at the equator.
The need for a higher-resolution global bathymetric chart has been highlighted in a paper titled "World bathymetric charts - On the requirement for a world wide bathymetric chart on a scale larger than the General Bathymetric Chart of the Oceans (GEBCO)". The paper aims to bring attention to the opportunity for producing a worldwide series of Bathymetric Charts and the need for Oceanographers to state their requirements for such charts.
The Seabed 2030 project, a major global initiative, is working towards mapping the ocean floor at much higher resolution. The project aims to produce a fully mapped ocean by 2030 with collaboration from over 185 contributing organizations worldwide. However, despite significant progress with nearly 30% of the seafloor mapped to modern standards as of 2025, approximately 72.7% of the ocean floor remains unmapped at higher resolution, especially in deep-sea and polar regions due to technical and cost challenges.
According to oceanographers and experts involved in these efforts, the key requirements for producing a world-wide, high-resolution bathymetric chart beyond GEBCO include extensive data collection from a combination of modern methods, international collaboration, robust data processing and management frameworks, addressing mapping challenges in harsh environments, and scaling up resolution to finer than the current GEBCO grid.
In summary, while GEBCO remains the primary global dataset, progress is actively being made towards higher-resolution worldwide bathymetric charts via Seabed 2030 and allied efforts, driven by advances in technology, expanded international cooperation, and the growing recognition of bathymetric data's value for environmental and economic uses.
Technology is playing a vital role in the advancement of nautical charting, particularly in the production of higher-resolution global bathymetric charts. This is evident in initiatives like Seabed 2030, where advances in technology enable more efficient data collection and management.
The creation of a high-resolution world-wide bathymetric chart requires not only technology but also collaboration in science, as oceanographers and experts need to collaborate to address mapping challenges in harsh environments and scale up resolution beyond the current GEBCO grid.
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