This article examines the critical role of private sector ocean data in advancing sustainable ocean governance from national waters to Areas Beyond National Jurisdiction (ABNJ). Despite its significant value, such data often remains inaccessible due to legal, technical, and contractual barriers. Building on recent policy developments, including the BBNJ Agreement, the Ocean Decade and IOC UNESCO frameworks, the paper highlights emerging obligations and opportunities for data sharing. It argues that embedding clear data-sharing requirements into permits and contracts is essential to operationalise private ocean data sharing frameworks. Strengthening interoperability, incentives, and institutional coordination can unlock private sector data to support science-based decision-making, equity, and global ocean sustainability goals.
Sustainable ocean governance is essential for advancing the blue economy by balancing economic growth, environmental protection, and social equity. Global frameworks such as United Nation’s Conference on Laws of the Seas (UNCLOS) and Sustainable Development Goal 14 guide nations in managing marine resources, yet many struggle to translate policies into practice due to institutional fragmentation and limited technological capacity. Using Nigeria as a case study, this paper examines the alignment of national blue economy initiatives with international standards, the effectiveness of institutional coordination, and progress in Marine Spatial Planning. It identifies legal gaps, data limitations, and enforcement challenges, and recommends targeted reforms to strengthen implementation and advance ocean governance.
Vessel offset surveys (VOS) are essential for accurately integrating hydrographic systems, ensuring correct positioning and mounting angles for sonars, and positioning and orientation systems within specified manufacturer accuracies, which are necessary to meet the expected hydrographic survey standards summarized in the International Hydrographic Organization’s publication S-44. This study examines factors affecting VOS accuracy, such as the number of station setups, baseline lengths, least square plane fitting, and instrument accuracies. Results indicate that multiple setups are required to achieve accurate mounting angles. Longer baselines improve accuracy, particularly for small sensors like an inertial measurement unit, while circular transducers benefit from fitting a plane with multiple points. This analysis supports standardizing VOS procedures to enhance VOS reliability and accuracy.
Fisheries are an essential ocean industry, generating billions annually and supporting the livelihoods of millions worldwide. Effective management depends on governments’ ability to collect and analyse fisheries data, including vessel movements, catch, and ownership information. This article examines the international legal frameworks that mandate such data collection, alongside national legal protections that may restrict data sharing beyond public authorities. It considers whether these limitations are justified, given the inherently transboundary nature of fisheries and the need for cross-border data exchange, particularly in efforts to combat illegal, unreported and unregulated (IUU) fishing.
Nearshore hydrographic surveying in the Canadian Arctic remains challenging, resulting in persistent charting gaps and high concern navigation risks. This paper introduces Community-Sourced Bathymetry , an approach engaging Inuit communities to conduct targeted, systematic bathymetric surveys using standard navigation instruments and applying basic hydrographic principles. Results from Inuit-led surveys demonstrate that the collected data compare favorably with historical Canadian Hydrographic Service single-beam echo sounder datasets still largely used in Arctic navigation products. By leveraging local presence and Inuit Traditional Knowledge, this approach provides a promising, scalable solution to enhance Arctic nearshore mapping, improve safety, and strengthen community involvement in hydrography.
The Canadian Hydrographic Service (CHS) uses several satellite derived products to enhance navigational safety, with Satellite-Derived Bathymetry (SDB) representing a key remote-sensing product. At the CHS, SDB supports mission planning through an iterative process in which preliminary models are developed to guide data acquisition and ensure crew safety, then refined with the collected survey data. Through successive iterations, refined SDB models demonstrate improvements in global performance metrics while extending model confidence across previously unsurveyed regions. Understanding the precision of SDB techniques, along with the accuracy and uncertainty of the resulting products, is essential for defining appropriate and responsible use of SDB in nautical products.
Rapid advances in satellite imagery, uncrewed aerial systems, and artificial intelligence now enable unprecedented detection of marine megafauna, yet protection remains uneven due to governance, economic, and data-access barriers. Drawing on projects in Canada’s EEZ, Antarctica, and areas beyond national jurisdiction, this Note illustrates how technical readiness outpaces institutional frameworks. It proposes integrating biodiversity information into the International Hydrographic Organization’s S-100 standard as a practical pathway to improve interoperability, adaptive management, and data equity. These steps provide practical near-term pathways to enhance monitoring, interoperability, and adaptive management for marine megafauna across diverse jurisdictions.
It is a pleasure and an honour, in my capacity as Director of the International Hydrographic Organization (IHO) and as a member of the IHO delegation to the 12th Conference of the IHO–IAG Advisory Board on the Law of the Sea (ABLOS), to introduce this selection of conference contributions published in The International Hydrographic Review (IHR).
This contribution demonstrates the applicability of vessel-based GNSS measurements for deriving a regional Mean Sea Level (MSL)-ellipsoidal separation model in the Dutch Caribbean. Legacy hydrographic survey data from the 2019 Caribbean survey campaign is combined with tidal observations, predicted tides, and satellite altimetry to address limitations of global satellite-derived MSL models in complex coastal environments. Vessel-derived separation values show close agreement with shore-based benchmarks after correction for Sea Level Rise, Vertical Land Movement, and seasonal variability, with residuals typically within a few centimetres. The results confirm vessel-based separation measurements as a practical solution for establishing vertical control in data-sparse coastal regions, supporting hydrographic surveying, coastal management, and sea-level adaptation in Small Island Developing States.
Decarbonisation rules are turning bunkering into an evidence problem. Fuel claims now pass through MRV (Monitoring, Reporting and Verification) files, port records, and ocean-observation data. This Note explains the main data sources, where they fail, and why data integrity matters for enforcement, due diligence, and insurance. It uses ammonia bunkering as a hard case because small errors can trigger safety, pollution, and legal exposure. A short caselet shows what an audit-ready evidence package looks like near a sensitive coast. Five practical takeaways suggest how hydrographic and observing communities can support accountable transition.
Malaysia has entered a new era in hydrography with the appointment of Rear Admiral Dr Najhan bin Md Said as the nation’s new Chief Hydrographer. His leadership marks a decisive step in advancing Malaysia’s capabilities in seabed mapping, marine geospatial data, and maritime domain awareness.
Sidescan sonars are a key tool for maritime mapping, object detection, and wreck inspection. This paper presents SidescanTools, an open-source software to process common sidescan data formats (XTF, JSF). The Python-based application provides core functionalities such as bottom detection, geometric and radiometric corrections, and gain normalisation, thereby enhancing data resolution and range. Processed results can be exported to georeferenced raster images. SidescanTools was developed within the frame of Ghostnetbusters, a project for the detection of small objects on sonar data in collaboration with sonoware GmbH/Kiel and Geomar Helmholtz Institute for Ocean Research, Kiel, funded by WTSH Schleswig Holstein.
This paper explores the ocean observation paradox undermining global marine plastic governance. While the 2024 ITLOS Climate Change Advisory Opinion affirms a stringent due diligence obligation under UNCLOS Part XII to monitor transboundary pollution according to best available science, UNCLOS Part XIII structurally hinders these efforts. Continuous autonomous systems of ocean observation are physically essential to monitor plastics across the ocean but remain structurally incompatible with rigid coastal State consent regimes in the EEZ. Resolving this jurisdictional friction requires carving out certain ocean monitoring activities from traditional Marine Scientific Research. The emerging Plastics Treaty could embed pragmatic, notification-based exemptions to operationalize the science necessary for effective environmental compliance and litigation.
From 9 to 11 October 2024, the city of Cádiz hosted the Third Portuguese-Spanish Hydrography Conference (3JLEH). For the first time since its creation, the conference was held on Spanish soil, marking a significant milestone in the history of Iberian cooperation in hydrography and marine sciences.
The present international law regime leaves doubts as regards the objective of protection of the underwater cultural heritage. A provision included in the 1982 treaty of general codification of international law of the sea can be understood in a counterproductive meaning, as implying freedom of fishing for this heritage under a first-come-first-served approach. The 2001 treaty that could specifically ensure the effective protection of the heritage has not yet received sufficiently broad participation by States.
An apparent dilemma is often presented to port operations as if safety of navigation and port efficiency were opposing forces. Estuaries with heavy loads of sediments pose challenges to both safety and efficiency and they have to be addressed at the same time. The two sides of the same coin. One important matter is the use of low frequency sonars and rheometers, frequently discarded by Hydrographers on the basis that they do not achieve sufficient accuracy for the safety of navigation. However, high frequency sonars are not suitable for areas rich in fluid mud as they can only detect the floating, variable water-mud interface. This work addressed these limitations confronting high frequency multibeam survey with double frequency single beam survey and density measurements to find half a meter of navigable mud below the minimum depth indicated in a high-frequency sonar survey. The work proposes a first step to define a very conservative and safe definition of nautical depth.
Predicting maritime incidents requires spatially aware techniques that account for complex geographic and operational dynamics. By applying Geographic Weighted Regression (GWR), Generalized Linear Regression (GLR), Forest-Based Classification and Regression (FBCR), and Empirical Bayesian Kriging (EBK), this research models the spatial distribution of vessel incidents across the Caribbean Sea. Key influencing variables include vessel traffic density, charted zone confidence, flag state, and vessel age. Results highlight regional hotspots such as the Panama Canal and Gulf of Paria. Comparative analysis demonstrates the strengths and limitations of each technique, informing the development of adaptive, location-specific maritime risk mitigation strategies.
This study develops an economic risk assessment framework for maritime accidents within Trinidad and Tobago’s Exclusive Economic Zone, representative of Small Island Developing States. The framework integrates market and contingent valuation methods under the Total Economic Value framework with probabilistic risk modelling of drifting collisions. Consequences, expressed on a five-tier monetary scale adapted from the Simplified IALA Risk Assessment method were combined with probability estimates to quantify annual risk. Results are presented spatially, showing annualised risks of USD 30,000 to 2.48 million, highest in north-western Trinidad. The framework offers a transferable, evidence-based tool for prioritising targeted maritime risk mitigation.
Maritime accidents remain a critical concern despite advancements in navigation technology and safety regulations. This paper examines maritime events over a 20-year period (2002–2021) using geostatistical analysis and GIS-based methods to identify key risk factors, trends, and high-risk zones. Analysis of the IMO’s Global Integrated Shipping Information System (GISIS) database highlights the influence of vessel type, flag state performance, accident timing, and geographical hotspots on incident frequency. Collisions, groundings, and fires/explosions are the most prevalent events, with aged vessels, open registries and outdated or incomplete hydrographic survey data posing significant risks. Poor flag state oversight, economic constraints, and human factors exacerbate maritime hazards. Although accident rates have declined, high-risk zones persist, necessitating stricter regulatory enforcement, fleet modernization, and improved accident reporting. Strengthening international collaboration and proactive risk management is crucial for ensuring safer global shipping operations, particularly in high-risk regions like the Caribbean Sea.
