Vessel traffic data, or Automatic Identification System (AIS) data, are collected by the U.S. Coast Guard through an onboard navigation safety device that transmits and monitors the location and characteristics of large vessels in U.S. and international waters in real time. In the U.S., the Coast Guard and commercial vendors collect AIS data, which can also be used for a variety of coastal planning purposes.The Bureau of Ocean Energy Management (BOEM) and the National Oceanic and Atmospheric Administration (NOAA) have worked jointly to repurpose and make available some of the most important records from the U.S. Coast Guard’s national network of AIS receivers. Information such as location, time, ship type, speed, length, beam, and draft have been extracted from the raw data and prepared for analyses in desktop GIS software.Vessel tracks show the location and characteristics of commercial, recreational, and other marine vessels as a sequence of positions transmitted by AIS. AIS signals are susceptible to interference, and this can result in a gap within a vessel track. Vessels can have one or more tracks of any length. Furthermore, tracks will not necessarily start or stop at a well-defined port, or when a vessel is not in motion.The distribution, type, and frequency of vessel tracks are a useful aid to understanding the risk of conflicting uses within a certain geographic area and are an efficient and spatially unbiased indicator of vessel traffic. These tracks are used to build respective AIS Vessel Transit Counts layers, summarized at a 100-meter grid cell resolution. A single transit is counted each time a vessel track passes through, starts, or stops within a grid cell.This item is curated by the MarineCadastre.gov team. Find more information at marinecadastre.gov.
Vessel traffic data or Automatic Identification Systems (AIS) are a navigation safety device that transmits and monitors the location and characteristics of many vessels in U.S. and international waters in real-time. In the U.S. the Coast Guard and industry collect AIS data, which can also be used for a variety of coastal management purposes. NOAA and BOEM have worked jointly to make available these data from the U.S. Coast Guards national network of AIS receivers. The original records were filtered to a one-minute frequency rate and were subsetted to depict the location and description of vessels broadcasting within the Exclusive Economic Zone. MarineCadastre.gov AIS data are divided by month and Universal Transverse Mercator (UTM) zone.
A vessel track shows the location and characteristics of commercial and recreational boats as a sequence of positions transmitted by an Automatic Identification System (AIS). AIS signals are susceptible to interference and this can result in a gap within a vessel track. The distribution, type, and frequency of vessel tracks are a useful aid to understanding the risk of conflicting uses within a certain geographic area. The vessel track positions in this data set are collected and recorded from land-based antennas as part of a national network operated by the U.S. Coast Guard.
The automatic identification system (AIS) is a navigation safety device that transmits and monitors the location and characteristics of many vessels in U.S. and international waters in real time. In the U.S., the Coast Guard and industry collect AIS data, which can also be used for a variety of coastal planning purposes. NOAA and BOEM have worked jointly to add value and make available some of the most important historical records from the U.S. Coast Guard's national network of AIS receivers. This data set represents annual vessel transit counts summarized at a 100-meter by 100-meter geographic area. A single transit is counted each time a vessel track passes through, starts, or stops within a 100-meter grid cell. Direct data download | MetadataThis item is curated by the MarineCadastre.gov team. Find more information at marinecadastre.gov.
The automatic identification system (AIS) is a navigation safety device that transmits and monitors the location and characteristics of many vessels in U.S. and international waters in real time. In the U.S., the Coast Guard and industry collect AIS data, which can also be used for a variety of coastal planning purposes. NOAA and BOEM have worked jointly to add value and make available some of the most important historical records from the U.S. Coast Guard's national network of AIS receivers. This data set represents annual vessel transit counts summarized at a 100-meter by 100-meter geographic area. A single transit is counted each time a vessel track passes through, starts, or stops within a 100-meter grid cell. Direct data download | MetadataThis item is curated by the MarineCadastre.gov team. Find more information at marinecadastre.gov.
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The dataset consists of vessel tracking data in the form of AIS observations in the Baltic Sea during years 2017-19. The AIS observations have been enriched with vessel metadata such as power
The automatic identification system (AIS) is a navigation safety device that transmits and monitors the location and characteristics of many vessels in U.S. and international waters in real time. In the U.S., the Coast Guard and industry collect AIS data, which can also be used for a variety of coastal planning purposes. NOAA and BOEM have worked jointly to add value and make available some of the most important historical records from the U.S. Coast Guard's national network of AIS receivers. This data set represents annual vessel transit counts summarized at a 100-meter by 100-meter geographic area. A single transit is counted each time a vessel track passes through, starts, or stops within a 100-meter grid cell. Direct data download | MetadataThis item is curated by the MarineCadastre.gov team. Find more information at marinecadastre.gov.
This web-based tool enables users to interactively download U.S. vessel traffic data across user-defined geographies and time periods. It also provides quick visualization of vessel traffic densities and patterns using underlying map services derived from the same point data that are available for download via the application.Vessel traffic data, or Automatic Identification System (AIS) data, are collected by the U.S. Coast Guard through an onboard navigation safety device that transmits and monitors the location and characteristics of large vessels in U.S. and international waters in real time. In the U.S., the Coast Guard and commercial vendors collect AIS data, which can also be used for a variety of coastal planning purposes.The Bureau of Ocean Energy Management (BOEM) and the National Oceanic and Atmospheric Administration (NOAA) have worked jointly to repurpose and make available some of the most important records from the U.S. Coast Guard’s national network of AIS receivers. Information such as location, time, ship type, speed, length, beam, and draft have been extracted from the raw data and prepared for analyses in desktop GIS software.BOEM and NOAA have also worked together to build a collection of tools and instructional materials available here: https://marinecadastre.gov/ais/. These are designed to help analysts process the data and derive products that improve offshore site analysis, use-conflict studies, and the understanding of marine transportation patterns.This item is curated by the MarineCadastre.gov team. Find more information at marinecadastre.gov.
The automatic identification system (AIS) is a navigation safety device that transmits and monitors the location and characteristics of many vessels in U.S. and international waters in real time. In the U.S., the Coast Guard and industry collect AIS data, which can also be used for a variety of coastal planning purposes. NOAA and BOEM have worked jointly to add value and make available some of the most important historical records from the U.S. Coast Guard's national network of AIS receivers. This data set represents annual vessel transit counts summarized at a 100-meter by 100-meter geographic area. A single transit is counted each time a vessel track passes through, starts, or stops within a 100-meter grid cell. Direct data download | MetadataThis item is curated by the MarineCadastre.gov team. Find more information at marinecadastre.gov.
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The data is compiled from the trajectory data of ships in the East China Sea (desensitized), which is the real historical ship trajectory data at sea. The data set covers information of multiple dimensions. Each trajectory data includes fishing boat ID, latitude and longitude, speed, direction, time, and operation method (including trawls, purse seines and gillnets) etc.
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Abstract:This layer an aggregation of annual vessel traffic from 2020. The Vessel Tracks have been derived from data sourced from the Australian Maritime Safety Authority. Converted into FGDB Time Field generated using Convert Time field geoprocessing Tool dd/MM/yyyy hh:mm:ss tt Unique Vessel ID generated by Field Calculator Type=Long, Numeric no decimal places Field Calc: ID=!CRAFT_ID!/100AIS Tracks build from MarineCadastre Trackbuilder Pro, downloadable from https://marinecadastre.gov/tools/The Craft Tracking System (CTS) and Mariweb are AMSA’s vessel traffic databases. They collect vessel traffic data from a variety of sources, including terrestrial and satellite shipborne Automatic Identification System (AIS) data sources. This dataset has been built from AIS data extracted from CTS, and it contains vessel traffic data for the year 2020. The dataset covers the extents of Australia’s Search and Rescue Region. Each point within the dataset represents a vessel position report and is spatially and temporally defined by geographic coordinates and a Universal Time Coordinate (UTC) timestamp respectively.Source data:© Commonwealth of Australia (Australian Maritime Safety Authority) 2020Further information available from AMSA:https://www.operations.amsa.gov.au/Spatial/DataServices/DigitalData
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This dataset contains version 3.0 (March 2025 release) of the Global Fishing Watch apparent fishing effort dataset. Data is available for 2012-2024 and based on positions of >190,000 unique automatic identification system (AIS) devices on fishing vessels, of which up to ~96,000 are active in a given year. Fishing vessels are identified via a machine learning model, vessel registry databases, and manual review by GFW and regional experts. Vessel time is measured in hours, calculated by assigning to each AIS position the amount of time elapsed since the previous AIS position of the vessel. The time is counted as apparent fishing hours if the GFW fishing detection model - a neural network machine learning model - determines the vessel is engaged in fishing behavior during that AIS position.
Data are spatially binned into grid cells that measure 0.01 or 0.1 degrees on a side; the coordinates defining each cell are provided in decimal degrees (WGS84) and correspond to the lower-left corner. Data are available in the following formats:
The fishing effort dataset is accompanied by a table of vessel information (e.g. gear type, flag state, dimensions).
Fishing effort and vessel presence data are available as .csv files in daily formats. Files for each year are stored in separate .zip files. A README.txt and schema.json file is provided for each dataset version and contains the table schema and additional information. There is also a README-known-issues-v3.txt file outlining some of the known issues with the version 3 release.
Files are names according to the following convention:
Daily file format:
[fleet/mmsi]-daily-csvs-[100/10]-v3-[year].zip
[fleet/mmsi]-daily-csvs-[100/10]-v3-[date].csv
Monthly file format:
fleet-monthly-csvs-10-v3-[year].zip
fleet-monthly-csvs-10-v3-[date].csv
Fishing vessel format: fishing-vessels-v3.csv
README file format: README-[fleet/mmsi/fishing-vessels/known-issues]-v3.txt
File identifiers:
[fleet/mmsi]: Data by fleet (flag and geartype) or by MMSI
[100/10]: 100th or 10th degree resolution
[year]: Year of data included in .zip file
[date]: Date of data included in .csv files. For monthly data, [date]corresponds to the first date of the month
Examples: fleet-daily-csvs-100-v3-2020.zip; mmsi-daily-csvs-10-v3-2020-01-10.csv; fishing-vessels-v3.csv; README-fleet-v3.txt; fleet-monthly-csvs-10-v3-2024.zip; fleet-monthly-csvs-10-v3-2024-08-01.csv
For an overview of how GFW turns raw AIS positions into estimates of fishing hours, see this page.
The models used to produce this dataset were developed as part of this publication: D.A. Kroodsma, J. Mayorga, T. Hochberg, N.A. Miller, K. Boerder, F. Ferretti, A. Wilson, B. Bergman, T.D. White, B.A. Block, P. Woods, B. Sullivan, C. Costello, and B. Worm. "Tracking the global footprint of fisheries." Science 361.6378 (2018). Model details are available in the Supplementary Materials.
The README-known-issues-v3.txt file describing this dataset's specific caveats can be downloaded from this page. We highly recommend that users read this file in full.
The README-mmsi-v3.txt file, the README-fleet-v3.txt file, and the README-fishing-vessels-v3.txt files are downloadable from this page and contain the data description for (respectively) the fishing hours by MMSI dataset, the fishing hours by fleet dataset, and the vessel information file. These readmes contain key explanations about the gear types and flag states assigned to vessels in the dataset.
File name structure for the datafiles are available below on this page and file schema can be downloaded from this page.
A FAQ describing the updates in this version and the differences between this dataset and the data available from the GFW Map and APIs is available here.
The apparent fishing hours dataset is intended to allow users to analyze patterns of fishing across the world’s oceans at temporal scales as fine as daily and at spatial scales as fine as 0.1 or 0.01 degree cells. Fishing hours can be separated out by gear type, vessel flag and other characteristics of vessels such as tonnage.
Potential applications for this dataset are broad. We offer suggested use cases to illustrate its utility. The dataset can be integrated as a static layer in multi-layered analyses, allowing researchers to investigate relationships between fishing effort and other variables, including biodiversity, tracking, and environmental data, as defined by their research objectives.
A few example questions that these data could be used to answer:
What flag states have fishing activity in my area of interest?
Do hotspots of longline fishing overlap with known migration routes of sea turtles?
How does fishing time by trawlers change by month in my area of interest? Which seasons see the most trawling hours and which see the least?
This global dataset estimates apparent fishing hours effort. The dataset is based on publicly available information and statistical classifications which may not fully capture the nuances of local fishing practices. While we manually review the dataset at a global scale and in a select set of smaller test regions to check for issues, given the scale of the dataset we are unable to manually review every fleet in every region. We recognize the potential for inaccuracies and encourage users to approach regional analyses with caution, utilizing their own regional expertise to validate findings. We welcome your feedback on any regional analysis at research@globalfishingwatch.org to enhance the dataset's accuracy.
Caveats relating to known sources of inaccuracy as well as interpretation pitfalls to avoid are described in the README-known-issues-v3.txt file available for download from this page. We highly recommend that users read this file in full. The issues described include:
Data from 2024 should be considered provisional, as vessel classifications may change as more data from 2025 becomes available.
MMSI is used in this dataset as the vessel identifier. While MMSI is intended to serve as the unique AIS identifier for an individual vessel, this does not always hold in practice.
The Maritime Identification Digits (MID), the first 3 digits of MMSI, are the only source of information on vessel flag state when the vessel does not appear on a registry. The MID may be entered incorrectly, obscuring information about an MMSI’s flag state.
AIS reception is not consistent across all areas and changes over time.
Query using SQL in the Global Fishing Watch public BigQuery dataset: global-fishing-watch.fishing_effort_v3
Download the entire dataset from the Global Fishing Watch Data Download Portal (https://globalfishingwatch.org/data-download/datasets/public-fishing-effort)
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This dataset corresponds to 6 months of AIS data of vessels steaming in the area of the Ushant traffic separation scheme (in Brittany, West of France). This is an area with one of the highest traffic density in the world, with a clear separation scheme with two navigation lanes. Different kinds of vessels are present in the area, from cargos and tankers with high velocity and straight routes to sailing boats or fishing vessels with low speed and different sailing directions. As such, the area is highly monitored to avoid collision or grounding, and a better analysis and understanding of the different ship behaviors is of prime importance.The whole trajectory data set consists in 18,603 trajectories, gathering overall more than 7 millions GPS observations. Only trajectories having more than 30 points were kept, time lag between two consecutive observations ranges between 5 seconds and 15 hours, with 95% of time lags below 3 minutes.Authors would like to thank CLS (Collecte Localisation Satellites) and Erwan Guegueniat for providing the raw data that allowed building this dataset.This work has been supported by DGA through the ANR/Astrid SESAME project (ref: ANR-16-ASTR-0026).
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AIS nmea sample dataset used for testing AIS decoding library. This dataset was originally published in https://github.com/aduvenhage/ais-decoder as a sample test dataset. The original dataset can be found at https://github.com/aduvenhage/ais-decoder/blob/master/data/nmea-sample.txt
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Derived from 2011 Automatic Identification System (AIS) broadcast returns. Each vessel count per aliquot block represents the number of vessels traveling through the block during the year of 2010. An aliquot measures 1/16 of a full OCS leasing block or 1200 x 1200 meters. Only areas where BOEM publishes Official Protraction Diagrams will contain the aliquot AIS counts, therefore, large areas of inland state waters may be missing aliquot AIS counts. The data has also been clipped so that any aliquot that touches land has been deleted so that the user can discern the location of the coastline. Vessel type breakdowns can be viewed using the ID tool or by downloading the data. To download the data please click the following links for the Atlantic portion and the West Coast portion of the data.
Attribution-NonCommercial 3.0 (CC BY-NC 3.0)https://creativecommons.org/licenses/by-nc/3.0/
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Abstract:This layer an aggregation of annual vessel traffic from 2020. The Vessel Tracks have been derived from data sourced from the Australian Maritime Safety Authority. Converted into FGDB Time Field generated using Convert Time field geoprocessing Tool dd/MM/yyyy hh:mm:ss tt Unique Vessel ID generated by Field Calculator Type=Long, Numeric no decimal places Field Calc: ID=!CRAFT_ID!/100AIS Tracks build from MarineCadastre Trackbuilder Pro, downloadable from https://marinecadastre.gov/tools/The Craft Tracking System (CTS) and Mariweb are AMSA’s vessel traffic databases. They collect vessel traffic data from a variety of sources, including terrestrial and satellite shipborne Automatic Identification System (AIS) data sources. This dataset has been built from AIS data extracted from CTS, and it contains vessel traffic data for the year 2020. The dataset covers the extents of Australia’s Search and Rescue Region. Each point within the dataset represents a vessel position report and is spatially and temporally defined by geographic coordinates and a Universal Time Coordinate (UTC) timestamp respectively.Source data:© Commonwealth of Australia (Australian Maritime Safety Authority) 2020Further information and data download available from AMSA:https://www.operations.amsa.gov.au/Spatial/DataServices/DigitalData
This dataset consists of 107 days of vessel tracking using the Automatic Identification System (AIS) at 1 hour intervals extracted for the Queensland region from the Spatial@AMSA Historic Vessel Tracking website (AMSA 2013). It has been converted to Shapefile format and contains just under 1 million points.
Note: The Spatial@AMSA Historic Vessel Tracking website is no longer available, however similar and more recent data is now available from Spatial@AMSA Vessel Tracking Data website (https://www.operations.amsa.gov.au/Spatial/DataServices/DigitalData).
Vessel tracking data is used to support coastal traffic management, search and rescue response and to meet requirements for safety and protection of the maritime environment. A valuable data set for marine use studies.
The Automatic Identification System (AIS) is an automatic tracking system used on ships and by vessel traffic services (VTS) for identifying and locating vessels by electronically exchanging data with other nearby ships, AIS base stations, and satellites. Each vessel regularly transmits its position ranging from 3 minutes for anchored or moored vessels, to 2 seconds for fast moving or manoeuvring vessels.
This dataset only contains vessel positions at approximately 1 hour internals. Even so each vessel can contribute many data points.
Class A transceivers have been mandated by the International Maritime Organization (IMO) for vessels of 300 gross tonnage and upwards engaged on international voyages, cargo ships of 500 gross tonnage and upwards not engaged on international voyages, as well as passenger ships (more than 12 passengers), irrespective of size. Class A transceivers are stronger, have priority transmissions and transmit more frequently then Class B transceivers.
Class B transceivers provide limited functionality and is intended for non-SOLAS vessels. It is not mandated by the International Maritime Organization (IMO) and has been developed for non-SOLAS commercial and recreational vessels.
The Historic Vessel Tracking Spatial@AMSA website provides a data download of historic vessel positions from April 2009 to current time minus 2 weeks.
The original data was downloaded through the Spatial@AMSA Historic Vessel Tracking Request website (https://www.operations.amsa.gov.au/Spatial/DataServices/CraftTrackingRequest). Due to limitations in the maximum size of the download, the data was requested in 3 day lots, using CSV download format and "Select by State" of QLD. All of the CSV files were compiled together using Notepad++, then loaded into ArcMap using Add Data / Add XY. This was then exported as a shapefile. This resulted in a very large shapefile as each of the columns were made excessively large (254 characters) by this process. To reduce the size of the shapefile a duplicate column was setup for each of the text attributes, except this time the size was set to just fit the data in. The data was copied to the new column using the field calculator and the original field deleted. This process reduced the database file of the shapefile from 1.4 GB to 170 MB.
Note that due to a limitation of the shapefile format the high resolution time stamps of vessels did not come out in the shapefile. This information is however available in the CSV version.
This dataset only contains information available from the Historic Vessel Tracking Spatial@AMSA website and only contains the ships course, speed, heading, ship name and if it is piloted. It does not contain information about the ship's length, breadth, cargo or status.
The e-Atlas has not confirmed what types of vessels this dataset contains however it probably contains most AIS Class A and some Class B vessels.
Format:
This dataset is available in Comma Separated Value (CSV) (80 MB) and Shapefile format (178 MB).
Data Dictionary:
CSV file: Not a lot is known about the fields of this dataset as they come from AMSA undocumented. Values in brackets are typical values. - CourseDegrees: (0, 331.3, 184) - CraftType: (Vessel) - FixTime: (9/05/2013 21:13) - Heading: Heading of the vessel in integer degrees, sometime there is no value (284) - IsPilotedVoyage: Boolean (FALSE, TRUE) - Latitude, Longitude: Vessel position in decimal degrees (-23.75092333, 151.1676367) - Name: Vessel id (NOMADIC MILDE, SMIT KULLAROO, HYUNDAI SUCCESS) - ReportingAgentName: (AMSA, AIS) - Speed: unknown units (0, 13.2)
Shapefile: These are the same values as for the CSV but renamed to fit limitations of shapefiles: CouseDegr, Heading, Latitude, Longitude, Speed, NameB, IsPiloted, FixTimeB, Reporting.
References:
Australian Maritime Safety Authority. (2013) Historical Vessel Tracking. Spatial@AMSA, [CSV data file]. License: Creative Commons Attribution-Noncommercial 3.0 Australia. Available: https://www.operations.amsa.gov.au/Spatial/DataServices/CraftTrackingRequest. Accessed 6 September 2013
A shore-based station that provides identity, time synchronization, and text messages, which report (message 4) every ten seconds and are identified by a 00MIDxxxxx MMSI. These stations can also transmit AIS ATON Reports (message 21) and Application Specific Messages (ASM, message 6 and message 8) for meteorological or hydrological information, marine safety information, etc. (see the IALA Application Specific Message Collection). The Coast Guard Light List maintains a list of U.S. stations that also act as AIS ATONs or transmit ASMs. In the United States, these stations are solely operated by the U.S. Coast Guard (USCG) in the Nationwide Automatic Identification System, a nationwide network that supports all USCG missions and is designed to enhance the Coast Guards maritime domain awareness of vessels operating in or approaching the nations waterways, ports, and infrastructure. This network, which comprises 130-plus base stations and 150-plus USACE inland stations, collects over 120 million AIS messages daily and shares information with other government agencies, industry, academia, and coastal planners.Direct data download | MetadataThis item is curated by the MarineCadastre.gov team. Find more information at marinecadastre.gov.
MIT Licensehttps://opensource.org/licenses/MIT
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The Vessel Density maps in the EU are created since the 2019 by Cogea for the European Marine Observation and Data Network (EMODnet). The dataset is updated every year and is available for viewing and download on EMODnet Human Activities web portal (www.emodnet-humanactivities.eu). The maps are based on AIS data yearly purchased from Collecte Localisation Satellites (CLS) and ORBCOMM. The maps, GeoTIFF format, show shipping density in 1x1km cells of a grid covering all EU waters and some neighbouring areas. Density is expressed as hours per square kilometre per month. The following ship types are available:0 Other, 1 Fishing, 2 Service, 3 Dredging or underwater ops, 4 Sailing, 5 Pleasure Craft, 6 High speed craft, 7 Tug and towing, 8 Passenger, 9 Cargo, 10 Tanker, 11 Military and Law Enforcement, 12 Unknown and All ship types. This particular layer refers to EMODnet ship type "All" that includes all the AIS ship Type codes.
The U.S. Vessel Traffic application is a web-based visualization and data-access utility created by Esri. Explore U.S. maritime activity, look for patterns, and download manageable subsets of this massive data set. Vessel traffic data are an invaluable resource made available to our community by the US Coast Guard, NOAA and BOEM through Marine Cadastre. This information can help marine spatial planners better understand users of ocean space and identify potential space-use conflicts. To download this data for your own analysis, explore the Download Options, navigate to a NOAA Electronic Navigation Chart area of interest, and make your selection. This data was sourced from the Automatic Identification System (AIS) provided by USCG, NOAA, and BOEM through Marine Cadastre and aggregated for visualization and sharing in ArcGIS Pro. This application was built with the ArcGIS API for JavaScript. Access this data as an ArcGIS Online collection here. Learn more about AIS tracking here. Find more ocean and maritime resources in Living Atlas. Inquiries can be sent to Keith VanGraafeiland.
Vessel traffic data, or Automatic Identification System (AIS) data, are collected by the U.S. Coast Guard through an onboard navigation safety device that transmits and monitors the location and characteristics of large vessels in U.S. and international waters in real time. In the U.S., the Coast Guard and commercial vendors collect AIS data, which can also be used for a variety of coastal planning purposes.The Bureau of Ocean Energy Management (BOEM) and the National Oceanic and Atmospheric Administration (NOAA) have worked jointly to repurpose and make available some of the most important records from the U.S. Coast Guard’s national network of AIS receivers. Information such as location, time, ship type, speed, length, beam, and draft have been extracted from the raw data and prepared for analyses in desktop GIS software.Vessel tracks show the location and characteristics of commercial, recreational, and other marine vessels as a sequence of positions transmitted by AIS. AIS signals are susceptible to interference, and this can result in a gap within a vessel track. Vessels can have one or more tracks of any length. Furthermore, tracks will not necessarily start or stop at a well-defined port, or when a vessel is not in motion.The distribution, type, and frequency of vessel tracks are a useful aid to understanding the risk of conflicting uses within a certain geographic area and are an efficient and spatially unbiased indicator of vessel traffic. These tracks are used to build respective AIS Vessel Transit Counts layers, summarized at a 100-meter grid cell resolution. A single transit is counted each time a vessel track passes through, starts, or stops within a grid cell.This item is curated by the MarineCadastre.gov team. Find more information at marinecadastre.gov.