Definition and important uses of CSB
The International Hydrographic Organization (IHO) defines Crowdsourced Bathymetry (CSB) as the collection and sharing of depth measurements from vessels using standard navigation instruments while engaged in routine maritime operations.
Crowdsourced bathymetry (CSB) data can provide a valuable, cost-effective method for supplementing traditional, high-precision hydrographic surveys. CSB can support filling gaps in the existing maps and charts of the world's oceans and waterways, foster a global community of ocean data contributors, all while utilizing vessels which are often non-scientific or non-systematic survey in nature. These can be anything from commercial fishing vessels, to dive boats, to leisure yachts. CSB programs rely on vessels equipped with common marine electronics, such as a depth transducer (echo sounder), a GPS unit, and ideally a motion reference unit (inertial navigation system), often linked through NMEA 2000 or NMEA 0183 networks. Together, these devices provide depth measurements tied to time and position, creating seafloor profiles as vessels move through the water and resulting in a map of the seafloor. As we move into an era of increasingly capable technology becoming more accessible and widespread among vessels, the door to utilizing the "crowd" has opened.
Some of the major strengths of CSB lie in its relative (and increasing) affordability as depth sounders become more capable and simultaneously more connected. This creates the potential for countries or organizations to collect seafloor data on a much larger scale than was previously possible. Additionally, it should be noted that CSB relies on vessels that are often smaller and have a shallower draft than hydrographic or research vessels. As a result, CSB can target shallow and narrow water bodies that have long been inaccessible with traditional tools. While CSB isn’t a cure-all solution, its specific strengths allow it to be useful in scenarios such as localized community waterway mapping, or first-time mapping of areas where more advanced tools are financially or physically inaccessible.
Data managers, scientists, hydrographic offices, and private companies alike can put this data to use for various outcomes. For example, the National Oceanic and Atmospheric Administration (NOAA) in the United States of America has utilized the CSB data collected along the Gulf and Atlantic Coasts of America to identify areas in which older and potentially outdated charts are misaligned with current data. This may indicate a need for re-surveying with advanced hydrographic tools, providing safer operation for all vessels utilizing coastal waters. With enough data density, eventually this data can also be utilized to integrate into official hydrographic charts.
Private companies, such as Raymarine, Olex, and Garmin use CSB to inform charts made by their company (e.g. Raymarine’s “RealBathy”), which in turn advise users on areas which may be shallower than expected. These tools help users to make more informed navigational decisions, avoiding areas that have been flagged as potentially shallow even if these readings are not verified by official hydrographic tools.
Another example can be found in work from NOAA’s CoastHydrographic SurveySystems Developmentand LabTechnology thatBranch, which scraped all CSB data from Seabed2030 within America’s Atlantic and Gulf Coasts to assess areas of disagreement between official charts and CSB data. Through this process, more than 315 million data points were collected and assessed for their agreement with nautical charts, and areas of discrepancy were identified and tagged for potential future hydrographic resurveying utilizing more advanced survey tools. In this way, CSB has helped to identify cases in which advanced tools should be utilized and has helped to prioritize areas of interest.
Hydrographic offices and research institutions are beginning to look into other ways these data can be applied, especially in localized areas where seafloor shapes have direct impact on coastal populations. For example, this data could help to enhance runup modelling, characterize tsunami impacts, results of hurricanes, and regular changes in dredged channels. A great example of CSB utility may be found in narrow waterways where isostatic rebound is causing waterways to become shallower, reducing navigability in waterways which may be vital for transport, recreation and industry.
CSB data can be used to inform local mapping efforts and policies, but can also contribute to global scientific efforts, like the Nippon Foundation-GEBCO Seabed 2030 Project whose aim is to completely map the world’s seafloor with direct measurements by 2030. Any CSB data can be contributed to the Seabed 2030 Project, and the general international community, by submitting it to the IHO’s Data Center for Digital Bathymetry (DCDB) via a Trusted Node. The “Trusted Node” conducts quality assurance on the data and then makes it available to the public, via the IHO DCDB.
The role of a trusted node is primarily to act as a secure source of data to the DCDB. This requires that someone be responsible for managing data flow from vessel into the DCDB, in line with the guidelines set up in the B-12 guiding document from the IHO. To become a trusted node, contact with the DCDB/NCEI is required. A list of existing trusted nodes exists here. Each trusted node has its own target audience; for example, the International SeaKeepers Society is primarily engaged with privately owned yachts and leisure boats, whereas the University of South Florida Center for Ocean Mapping and Innovative Technologies (COMIT) primarily engages all types of vessels within the Tampa Bay region. Finding the right trusted node to fit your vessel helps to streamline this process. To enroll your own organization as a trusted node, review the guidance on the CSB tab of the IHO DCDB website, and contact the DCDB via email: bathydata@iho.int.
DCDB contact for inquiries about becoming a Trusted Node: bathydata@iho.int