Gulf of Mexico Depth Contours derived from NOAA's NGDC bathymetric grids and from BOEM's seismic grid compilation. Both NOAA and BOEM contours are shown in meters or feet depending on the user's preference. Contours were created to compare and contrast the older NOAA NGDC grid to the newer BOEM gridded bathymetry described below: BOEM's deepwater Gulf of Mexico bathymetry grid. Created by mosaicing over 100 3D seismic surveys. XY grid size is 40ft and depth is in feet. Depth accurate to 0.1% (one-tenth of one-percent) of water depth in most places. Depth accuracy decreases slightly when approaching minimum (-200ft) and maximum (-11,000ft) depth extents due to the nature of the depth transformation method used. BOEM thanks the following companies for allowing BOEM use of their data to create this new map: CGG Services (U.S.) Inc., Houston, TX; Exxon; Geophysical Pursuit; PGS; Seitel; TGS; and WesternGeco, LLC.

BOEM's deepwater Gulf of Mexico bathymetry grid was created by mosaicing over 100 3D seismic surveys. XY grid size is 40ft and depth is in feet. Hillshaded rasters showcase the dynamic bathymetric relief of the seafloor and were created using parameters of sun direction from due North at an angle of 45 degrees, with vertical exaggeration of 5. Pyramid files in ArcMap have been generated to allow users to quickly visualize the data at varying scales.Depth is accurate to 0.1% (one-tenth of one-percent) of water depth in most places. Depth accuracy decreases slightly when approaching minimum (-200ft) and maximum (-11,000ft) depth extents, due to the nature of the depth transformation method used. The Bureau of Ocean Energy Management makes publically available a new deepwater bathymetry grid of the northern Gulf of Mexico, created by utilizing 3D seismic data which covers more than 90,000 square miles. The grid provides enhanced resolution compared to existing public bathymetry maps over the region, delivering 10 to 50 times increased horizontal resolution of the salt mini-basin province, abyssal plain, Mississippi Fan, and the Florida Shelf/Escarpment. To create the grid the seafloor was interpreted on over one-hundred 3D seismic time-migrated surveys, then mosaicked together and converted to depth in feet. The grid consists of 1.4 billion, 40-by-40 ft defined cells covering water depths –130 to –11,087 ft (–40 to –3,379 m). The average error is calculated to be 1.3 percent of water depth.BOEM has the responsibility of issuing permits for the acquisition of geophysical data in U.S. Federal waters as designated under the Outer Continental Shelf (OCS) Lands Act. Regulations at 30 CFR 551 allow BOEM to obtain a digital version of any post-processed, post-migrated two-dimensional (2D) and three-dimensional (3D) seismic survey acquired within the OCS. BOEM now maintains a confidential library of approximately 1,700 time and depth 2D/3D seismic surveys for the Gulf of Mexico (GOM), with survey vintages dating back to the early 1980s. These data provide geoscientists a world-class repository of subsurface digital data to interpret and utilize in achieving our regulatory missions.Since 1998, BOEM has used the largest, highest quality 3D time surveys to interpret the seafloor. Time surveys were used because the primary objective was not bathymetry but to identify seafloor acoustic amplitude anomalies indicative of authigenic carbonate hardgrounds and natural hydrocarbon seepage; those areas which may be suitable habitat for communities of chemosynthetic, coral, and other benthic organisms [Roberts, 1996, Roberts et al., 1992 and 2000]. The acoustic amplitude response of the seafloor is better resolved in time-migrated surveys rather than depth-migrated, allowing for increased accuracy in the identification of potential benthic habitats and seeps. While this new bathymetry grid does not include acoustic amplitude data for the seafloor, BOEM does publish polygon shapefiles which outline areas of anomalously high and low seafloor acoustic reflectivity, which can be downloaded at www.boem.gov/Seismic-Water-Bottom-Anomalies-Map-Gallery.Roberts, H.H., (1996), Surface amplitude data: 3D-Seismic for interpretation of seafloor geology (Louisiana slope): Gulf Coast Association of Geological Societies Transactions, v. 46, p. 353–362.Roberts, H.H., D.J. Cook, and M.K. Sheedlo, (1992), Hydrocarbon seeps of the Louisiana continental slope: Seismic amplitude signature and seafloor response: Gulf Coast Association of Geological Societies Transactions v. 42, p. 349–362.Roberts, H.H., J. Coleman, J. Hunt Jr., and W.W. Shedd, (2000), Surface amplitude mapping of 3D-seismic for improved interpretations of seafloor geology and biology from remotely sensed data, Gulf Coast Association of Geological Societies Transactions, v. 50, p. 495–503.

Gulf of Mexico Depth Grid Cells derived from BOEM's seismic grid compilation. BOEM's deepwater Gulf of Mexico bathymetry grid. Created by mosaicing over 100 3D seismic surveys. XY grid size is 40ft and depth is in feet. Depth accurate to 0.1% (one-tenth of one-percent) of water depth in most places. Depth accuracy decreases slightly when approaching minimum (-200ft) and maximum (-11,000ft) depth extents due to the nature of the depth transformation method used. BOEM thanks the following companies for allowing BOEM use of their data to create this new map: CGG Services (U.S.) Inc., Houston, TX; Exxon; Geophysical Pursuit; PGS; Seitel; TGS; and WesternGeco, LLC.

BOEM's deepwater Gulf of Mexico bathymetry grid was created by mosaicing over 100 3D seismic surveys. XY grid size is 40ft and depth is in feet. Depth is accurate to 0.1% (one-tenth of one-percent) of water depth in most places. Depth accuracy decreases slightly when approaching minimum (-200ft) and maximum (-11,000ft) depth extents, due to the nature of the depth transformation method used. The Bureau of Ocean Energy Management makes publically available a new deepwater bathymetry grid of the northern Gulf of Mexico, created by utilizing 3D seismic data which covers more than 90,000 square miles. The grid provides enhanced resolution compared to existing public bathymetry maps over the region, delivering 10 to 50 times increased horizontal resolution of the salt mini-basin province, abyssal plain, Mississippi Fan, and the Florida Shelf/Escarpment. To create the grid the seafloor was interpreted on over one-hundred 3D seismic time-migrated surveys, then mosaicked together and converted to depth in feet. The grid consists of 1.4 billion, 40-by-40 ft defined cells covering water depths –130 to –11,087 ft (–40 to –3,379 m). The average error is calculated to be 1.3 percent of water depth.BOEM has the responsibility of issuing permits for the acquisition of geophysical data in U.S. Federal waters as designated under the Outer Continental Shelf (OCS) Lands Act. Regulations at 30 CFR 551 allow BOEM to obtain a digital version of any post-processed, post-migrated two-dimensional (2D) and three-dimensional (3D) seismic survey acquired within the OCS. BOEM now maintains a confidential library of approximately 1,700 time and depth 2D/3D seismic surveys for the Gulf of Mexico (GOM), with survey vintages dating back to the early 1980s. These data provide geoscientists a world-class repository of subsurface digital data to interpret and utilize in achieving our regulatory missions.Since 1998, BOEM has used the largest, highest quality 3D time surveys to interpret the seafloor. Time surveys were used because the primary objective was not bathymetry but to identify seafloor acoustic amplitude anomalies indicative of authigenic carbonate hardgrounds and natural hydrocarbon seepage; those areas which may be suitable habitat for communities of chemosynthetic, coral, and other benthic organisms [Roberts, 1996, Roberts et al., 1992 and 2000]. The acoustic amplitude response of the seafloor is better resolved in time-migrated surveys rather than depth-migrated, allowing for increased accuracy in the identification of potential benthic habitats and seeps. While this new bathymetry grid does not include acoustic amplitude data for the seafloor, BOEM does publish polygon shapefiles which outline areas of anomalously high and low seafloor acoustic reflectivity, which can be downloaded at www.boem.gov/Seismic-Water-Bottom-Anomalies-Map-Gallery.Roberts, H.H., (1996), Surface amplitude data: 3D-Seismic for interpretation of seafloor geology (Louisiana slope): Gulf Coast Association of Geological Societies Transactions, v. 46, p. 353–362.Roberts, H.H., D.J. Cook, and M.K. Sheedlo, (1992), Hydrocarbon seeps of the Louisiana continental slope: Seismic amplitude signature and seafloor response: Gulf Coast Association of Geological Societies Transactions v. 42, p. 349–362.Roberts, H.H., J. Coleman, J. Hunt Jr., and W.W. Shedd, (2000), Surface amplitude mapping of 3D-seismic for improved interpretations of seafloor geology and biology from remotely sensed data, Gulf Coast Association of Geological Societies Transactions, v. 50, p. 495–503.

This DEM includes 10-meter bathymetry for the Mississippi Coast area including Hancock, Harrison, and Jackson Counties.While every effort has been made to ensure that these data are accurate and reliable within the limits of the current state of the art, NOAA cannot assume liability for any damages caused by any errors or omissions in the data, nor as a result of the failure of the data to function on a particular system. NOAA makes no warranty, expressed or implied, nor does the fact of distribution constitute such a warranty.The dataset is provided "as is," without warranty to its performance, merchantable state, or fitness for any particular purpose. The entire risk associated with the results and performance of this dataset is assumed by the user. This dataset should be used strictly as a planning reference and not for navigation, permitting, or other legal purposes.

This GIS overlay is a component of the U. S Geological Survey, Woods Hole Field Center's, Gulf of Mexico ArcView GIS database. The Gulf of Mexico GIS database is intended to organize and display USGS held data and provide on-line (WWW) access to the data and/or metadata.

This DEM includes 10-meter bathymetry for the southern Louisiana Gulf of Mexico coast including St. Mary, Terrebonne, Lafourche, Jefferson, and Plaquemines Parishes.While every effort has been made to ensure that these data are accurate and reliable within the limits of the current state of the art, NOAA cannot assume liability for any damages caused by any errors or omissions in the data, nor as a result of the failure of the data to function on a particular system. NOAA makes no warranty, expressed or implied, nor does the fact of distribution constitute such a warranty.The dataset is provided "as is," without warranty to its performance, merchantable state, or fitness for any particular purpose. The entire risk associated with the results and performance of this dataset is assumed by the user. This dataset should be used strictly as a planning reference and not for navigation, permitting, or other legal purposes.

NOAA's National Geophysical Data Center (NGDC) is building high-resolution digital elevation models (DEMs) for select U.S. coastal regions. These integrated bathymetric-topographic DEMs are used to support tsunami forecasting and modeling efforts at the NOAA Center for Tsunami Research, Pacific Marine Environmental Laboratory (PMEL). The DEMs are part of the tsunami forecast system SIFT (Short-term Inundation Forecasting for Tsunamis) currently being developed by PMEL for the NOAA Tsunami Warning Centers, and are used in the MOST (Method of Splitting Tsunami) model developed by PMEL to simulate tsunami generation, propagation, and inundation. Bathymetric, topographic, and shoreline data used in DEM compilation are obtained from various sources, including NGDC, the U.S. National Ocean Service (NOS), the U.S. Geological Survey (USGS), the U.S. Army Corps of Engineers (USACE), the Federal Emergency Management Agency (FEMA), and other federal, state, and local government agencies, academic institutions, and private companies. DEMs are referenced to the vertical tidal datum of Mean High Water (MHW) and horizontal datum of World Geodetic System 1984 (WGS84). Grid spacings for the DEM ranges from 1/3 arc-second (~10 meters) to 3 arc-seconds (~90 meters).This DEM includes the Key West, Florida area of Monroe County (not the mainland portion of the county).While every effort has been made to ensure that these data are accurate and reliable within the limits of the current state of the art, NOAA cannot assume liability for any damages caused by any errors or omissions in the data, nor as a result of the failure of the data to function on a particular system. NOAA makes no warranty, expressed or implied, nor does the fact of distribution constitute such a warranty.The dataset is provided "as is," without warranty to its performance, merchantable state, or fitness for any particular purpose. The entire risk associated with the results and performance of this dataset is assumed by the user. This dataset should be used strictly as a planning reference and not for navigation, permitting, or other legal purposes.

This shapefile shows the 10 meter contour interval based on the 5-meter multibeam bathymetry (Dartnell and Gardner, 1999) from the Flower Garden Banks region.

GEBCO’s gridded bathymetric data set, the GEBCO_2020 grid, is a global terrain model for ocean and land at 15 arc-second intervals.Original data source: https://www.gebco.net/data_and_products/gridded_bathymetry_data/This depth contours are generated from GEBCO's gridded bathymetry which is clipped by GCOOS Region (https://gis.gcoos.org/arcgis/rest/services/Stations/The_GCOOS_Region/MapServer/2). There are 4 different datasets: 1) 500m interval, namely 500m, 1000m, 1500m, 2000m, 2500m, 3000m, 3500m depth contours. 2) 100m interval, 3) 10m interval. 4) Selected (filtered) contours (10, 20, 30, 40, 50, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 1500, 2000, 2500, 3000, 3500m)

NGDC's U.S. Coastal Relief Model (CRM) provides the first comprehensive view of the U.S. coastal zone integrating offshore bathymetry with land topography into a seamless representation of the coast. The CRM spans the U.S. East and West Coasts, the northern coast of the Gulf of Mexico, Puerto Rico, and Hawaii, reaching out to, and in places even beyond, the continental slope. Bathymetric and topographic data sources include: NGDC's NOS hydrographic surveys, multibeam bathymetry, and trackline bathymetry; the U.S. Geological Survey (USGS); and other federal government agencies and academic institutions. Bathymetric contours from the International Bathymetric Chart of the Caribbean Sea and the Gulf of Mexico project were also used. Digital elevation models (DEMs) of the Great Lakes, Southern Alaska, and high-resolution DEMs of U.S. coastal communities and territories are also available.

This digital elevation model (DEM) is a part of a series of DEMs produced for the National Oceanic and Atmospheric Administration Coastal Services Center's Sea Level Rise and Coastal Flooding Impacts Viewer (www.csc.noaa.gov/slr/viewer). The DEMs created for this project were developed using the NOAA National Weather Service's Weather Forecast Office (WFO) boundaries. Because the WFO boundaries can cover large areas, the WFO DEM was divided into smaller DEMs to ensure more manageable file sizes. This metadata record describes the DEM for the Okaloosa (southern coastal portion only), Walton, Bay, Gulf, Franklin (western portion only), and Wakulla (western portion only) Counties. The DEM includes the best available lidar data known to exist at the time of DEM creation for the coastal areas of Okaloosa (southern coastal portion only), Walton, Bay, Gulf, Franklin (western portion only), and Wakulla (western portion only) counties, that met project specification. This DEM is derived from LiDAR collected for the Northwest Florida Water Management District (NWFWMD) and the Florida Department of Emergency Management (FDEM). Hydrographic breaklines used in the creation of the DEM were obtained from FDEM and Southwest Florida Water Management District (SWFWMD). This DEM is hydro flattened such that water elevations are less than or equal to 0 meters.This DEM is referenced vertically to the North American Vertical Datum of 1988 (NAVD88) with vertical units of meters and horizontally to the North American Datum of 1983 (NAD83). The resolution of the DEM is approximately 5 meters.The NOAA Coastal Services Center has developed high-resolution digital elevation models (DEMs) for use in the Center's Sea Level Rise And Coastal Flooding Impacts internet mapping application. These DEMs serve as source datasets used to derive data to visualize the impacts of inundation resulting from sea level rise along the coastal United States and its territories.The dataset is provided "as is," without warranty to its performance, merchantable state, or fitness for any particular purpose. The entire risk associated with the results and performance of this dataset is assumed by the user. This dataset should be used strictly as a planning reference and not for navigation, permitting, or other legal purposes.

NOAA's National Geophysical Data Center (NGDC) is building high-resolution digital elevation models (DEMs) for select U.S. coastal regions. These integrated bathymetric-topographic DEMs are used to support tsunami forecasting and modeling efforts at the NOAA Center for Tsunami Research, Pacific Marine Environmental Laboratory (PMEL). The DEMs are part of the tsunami forecast system SIFT (Short-term Inundation Forecasting for Tsunamis) currently being developed by PMEL for the NOAA Tsunami Warning Centers, and are used in the MOST (Method of Splitting Tsunami) model developed by PMEL to simulate tsunami generation, propagation, and inundation. Bathymetric, topographic, and shoreline data used in DEM compilation are obtained from various sources, including NGDC, the U.S. National Ocean Service (NOS), the U.S. Geological Survey (USGS), the U.S. Army Corps of Engineers (USACE), the Federal Emergency Management Agency (FEMA), and other federal, state, and local government agencies, academic institutions, and private companies. DEMs are referenced to the vertical tidal datum of Mean High Water (MHW) and horizontal datum of World Geodetic System 1984 (WGS84). Grid spacings for the DEM ranges from 1/3 arc-second (~10 meters) to 3 arc-seconds (~90 meters).This DEM includes the Corpus Christi, Texas area encompassing Nueces, Kleberg, San Patricio, and Aransas Counties.While every effort has been made to ensure that these data are accurate and reliable within the limits of the current state of the art, NOAA cannot assume liability for any damages caused by any errors or omissions in the data, nor as a result of the failure of the data to function on a particular system. NOAA makes no warranty, expressed or implied, nor does the fact of distribution constitute such a warranty.The dataset is provided "as is," without warranty to its performance, merchantable state, or fitness for any particular purpose. The entire risk associated with the results and performance of this dataset is assumed by the user. This dataset should be used strictly as a planning reference and not for navigation, permitting, or other legal purposes.

The Bathymetric Dynamic Digital Elevation Model (BDDEM) was developed using open source software. The BDDEM's initial basis was obtained by merging the five digital elevation models of the Northern Gulf region released by the National Centers for Environmental Information. The final build of the BDDEM includes all of the National Ocean Service hydrographic surveys conducted in Alabama, Mississippi and Louisiana through 2011. The digital elevation model (BDDEM) is available at resolutions of 3, 1 and 1/3 arc seconds.

Digital Elevation Model of the Gulf of Mexico, Integrating Bathymetric and Topographic Datasets

This dataset is the bathymetry Digital Elevation Model for the northern Gulf of Mexico coast including most or portions of the southeastern parishes of Louisiana, the coastal counties of Mississippi and Alabama, and the western counties of the Florida panhandle. The dataset includes offshore data extending, in some places, to a distance of ~200 km from the coast.NOAA's National Geophysical Data Center (NGDC) is building high-resolution digital elevation models (DEMs) for select U.S. coastal regions in the Gulf of Mexico. These integrated bathymetric-topographic DEMs were developed for NOAA Coastal Survey Development Laboratory (CSDL) through the American Recovery and Reinvestment Act (ARRA) of 2009 to evaluate the utility of the Vertical Datum Transformation tool (VDatum), developed jointly by NOAA's Office of Coast Survey (OCS), National Geodetic Survey (NGS), and Center for Operational Oceanographic Products and Services (CO-OPS).Bathymetric, topographic, and shoreline data used in DEM compilation are obtained from various sources, including NGDC, the U.S. Coastal Services Center (CSC), the U.S. Office of Coast Survey (OCS), the U.S. Army Corps of Engineers (USACE), and other federal, state, and local government agencies, academic institutions, and private companies.DEMs are referenced to the vertical tidal datum of North American Vertical Datum of 1988 (MHW), Mean High Water (MHW) or Mean Lower Low Water (MLLW) and horizontal datum of North American Datum of 1983 (NAD 83). Cell size ranges from 1/3 arc-second (~10 meters) to 1 arc-second (~30 meters). The NOAA VDatum DEM Project was funded by the American Recovery and Reinvestment Act (ARRA) of 2009 (http://www.recovery.gov/).The horizontal accuracy of bathymetric and topographic features in the DEM is dependent upon the accuracy of the input datasets used to determine corresponding cell values. Topography: 10 meters due to cell size. Lidar: less than 5 meters. DEM cell-value relative-contribution factors: Louisiana Lidar, Mississippi Lidar, CSC Lidar: 100, Mississippi Merged Lidar: 80, Digitzed features: 1, Bathymetry: 5 to several tens of meters. Positional accuracy of input bathymetric datasets limits accuracy of corresponding cell values in DEM. CSC Lidar: 0.75 meters. Early 20th-century NOS hydrographic soundings are limited by sparseness of deep-water soundings, and potentially large position accuracy of pre-satellite (i.e., GPS) navigation: tens to several tens of meters. Morphologic change in inland rivers and along the coast also degrades the positional accuracy of DEM features. DEM cell-value relative-contribution factors: CSC Coastal Lidar: 100, USACE hydrographic survey data: 5, NOS hydrographic soundings: 5, Digitized features: 1.The vertical accuracy of bathymetric and topographic features in the DEM is dependent upon the accuracy of the input datasets used to determine corresponding cell values. Topography: 1 to 16 meters. Vertical accuracy of input topographic datasets limits accuracy of corresponding cells in DEM. Lidar: less than 1 meter. DEM cell relative-contribution factors: Louisiana Lidar, Mississippi Lidar, CSC Lidar: 100, Digitized features: 10. Bathymetry: 0.1 meters to 5% of water depth. Vertical accuracy of input bathymetric datasets limits accuracy of corresponding cells in DEM. Early 20th-century NOS hydrographic soundings are limited by sparseness of deep-water soundings, and potentially large position accuracy of pre-satellite (i.e., GPS) navigation: several meters. DEM cell relative-contribution factors: CSC Coastal Lidar: 100, USACE hydrographic survey data: 5, NOS hydrographic soundings: 5, Digitized features: 1. Gridding interpolation to determine cell values between sparse NOS hydrographic soundings in deep water degrades the vertical accuracy of deep-water elevations.

High resolution (0.01° x 0.01°)Gulf of Mexico bathymetric grid, version 2.0 generated in February 2013. Data are in NetCDF-3 classic format. Luis Zamudio-Lopez (NRL, Luis.Zamudio@nrlssc.navy.mil) kindly offered an initial 1=100°(~1000 m) bathymetric grid for the region. This grid has been computationally modified and substantially hand edited (a) to better match the shoreline definition, (b) fill the voids in the water depths and (c) if possible, to more accurate represent the interpolated water depths. The final numerical grid conforms to the 1=25°(~4000 m) North Atlantic HYCOM computational domain, where they are both matched at 76:40 oW longitude. Data used in the development of the new grid include GSHHS: A Global Self-consistent, Hierarchical, High-resolution Shoreline Database, GEBCO 30 arc-sec global grid, a global high resolution 911x944m bathymetry (GMRT: The Global Multi-Resolution Topography) ,and the National Geophysical Data Center’s (NGDC) 6 arc-sec U.S. Coastal Relief Model database, volumes: 2, 3, 4 and 5.

https://gis.gcoos.org/arcgis/rest/services/Bathymetry/srtm15_v21_gshhs_clip_wgs84/ImageServerThis dataset is the NOAA NCEI SRTM15+ v2.1 (11 February 2020) clipped to the area containing and immediately surrounding the Gulf of Mexico.To provide an improved mapping of the seafloor fabric globally, NOAA NCEI have used available sounding data along with an improved global marine gravity model to develop at grid at 15 arcsecond resolution (~500 m). Land elevations are based on the best available data from SRTM, ASTER digital elevation models while the ice topography of Greenland and Antarctica is based on CryoSat-2 and IceSat. Ocean bathymetry is based on bathymetric predictions from the latest global gravity model from CryoSat-2 and Jason-1 along with 494 million carefully edited depth soundings at 15 arcsecond resolution.NOAA NCEI have used the bathymetry grid along with the improved gravity to construct a global map of abyssal hill amplitude and orientations and compare the orientations with predictions from seafloor age gradient analysis. Areas of disagreement reveal propagating rifts, microplates, and tectonic reorganizations. This SRTM15_PLUS provides the foundational bathymetry layer for Google Earth and is freely available at NOAA NCEI ftp site (topex.ucsd.edu).

This DEM includes 10-meter bathymetry for the Florida Gulf of Mexico coast including Bay, Walton, and Gulf Counties.While every effort has been made to ensure that these data are accurate and reliable within the limits of the current state of the art, NOAA cannot assume liability for any damages caused by any errors or omissions in the data, nor as a result of the failure of the data to function on a particular system. NOAA makes no warranty, expressed or implied, nor does the fact of distribution constitute such a warranty.The dataset is provided "as is," without warranty to its performance, merchantable state, or fitness for any particular purpose. The entire risk associated with the results and performance of this dataset is assumed by the user. This dataset should be used strictly as a planning reference and not for navigation, permitting, or other legal purposes.

High resolution (0.01° x 0.01°)Gulf of Mexico bathymetric grid, version 1.0 generated in August 2011. Data are in HYCOM native format. Luis Zamudio-Lopez (NRL, Luis.Zamudio@nrlssc.navy.mil) kindly offered an initial 1=100°(~1000 m) bathymetric grid for the regionThis grid has been computationally modified and substantially hand edited (a) to better match the shoreline definition, (b) fill the voids in the water depths and (c) if possible, to more accurate represent the interpolated water depths. The final numerical grid conforms to the 1=25°(~4000 m) North Atlantic HYCOM computational domain, where they are both matched at 76:40 oW longitude. Data used in the development of the new grid include GSHHS: A Global Self-consistent, Hierarchical, High-resolution Shoreline Database, GEBCO 30 arc-sec global grid, and the National Geophysical Data Center’s (NGDC) 6 arc-sec U.S. Coastal Relief Model database, volumes: 2, 3, 4 and 5.