Christopher C. Bemelmans Nancy T. DeWitt Jenna A. Brown 20260424 tabular, vector, and raster digital data Christopher C. Bemelmans Nancy T. DeWitt Jenna A. Brown 20260424 U.S. Geological Survey data release doi:10.5066/P13I93P7 St. Petersburg, Florida U.S. Geological Survey - St. Petersburg Coastal and Marine Science Center https://doi.org/10.5066/P13I93P7 In June 2025, the U.S. Geological Survey St. Petersburg Coastal and Marine Science Center (USGS SPCMSC) participated in a multidisciplinary geoscientific field data collection at Midnight Pass and Milton Pass located along Florida s west-central coastline. These inlets were opened as a result of hurricanes Helene and Milton in 2024. Researchers with the Nearshore Extreme Events Reconnaissance Association (NEER, https://neerassociation.org/) conducted surveys of these inlets immediately following Hurricane Milton in 2024, and this data collected in 2025 is to support the continued monitoring of the evolution of the inlets (Stark and others, 2025). This metadata record describes the single-beam bathymetry survey conducted by the USGS-SPCMSC at Midnight Pass, Florida on June 25, 2025, under the USGS Field Activity Number (FAN) 2025-313-FA. The survey area encompassed the nearshore environment, the inlet, and the back bay waterway resulting in 3.94 square kilometers (km2) of coverage at Midnight Pass. The single-beam bathymetry was acquired using two 12-foot personal watercrafts (PWC), outfitted with high precision Global Navigation Satellite System (GNSS) receivers, motion reference units, and survey-grade single-beam echosounders (SBES). This data release provides point data (x,y,z) in two reference frames: 1) World Geodetic System 1984 (WGS84) realization G2296, Universal Transverse Mercator (UTM) zone 17 North (N) for the horizontal, and WGS84 (G2296) ellipsoidal height in meters for the vertical; and 2) North American Datum of 1983 (NAD83) realization of 2011 for the horizontal, and North American Vertical Datum 1988 (NAVD88) orthometric height in meters with respect to GEOID18 for the vertical. Additional files include single-beam trackline shapefiles (.shp). For further information regarding data collection and/or processing steps, please see the metadata associated with this data release. Following the 2024 hurricane season, the USGS SPCMSC conducted a single-beam bathymetric survey within and around the vicinity of Midnight Pass as part of a comprehensive project in collaboration with academic institutions and federal agencies. A variety of techniques were applied to investigate the geomorphology of these areas, aiming to enhance understanding of how breach sites evolve following hurricane events. The primary goal of this cooperative effort was to consolidate, organize, and disseminate the field-collected data, ultimately resulting in a detailed and robust dataset. These data will guide forthcoming publication initiatives. Updates regarding publications will be communicated as they become available. Single-beam data and associated files were collected during USGS Field Activity Number (FAN) 2025-313-FA. Research Vessel (R/V) specific single-beam bathymetry echosounder data (SBES) were assigned subFANs; 25BIM03 (R/V Shark - WVR1) and 25BIM04 (R/V Chum - WVR2). This metadata file supports the Midnight Pass dataset collected on 06/25/2025, day of year 176. These data should not be used for navigational purposes. Additional survey and data details are available from the USGS Coastal and Marine Geoscience Data System (CMGDS) at, https://cmgds.marine.usgs.gov/services/activity.php?fan=2025-313-FA. 20250625 ground condition Complete None planned -82.5169590 -82.5032405 27.2120048 27.2032678 USGS Metadata Identifier USGS:8be053c8-e25b-4565-83be-0f1c955cbedf ISO 19115 Topic Category geoscientificInformation elevation oceans location imageryBaseMapsEarthCover Global Change Master Directory EARTH SCIENCE > OCEANS > BATHYMETRY/SEAFLOOR TOPOGRAPHY > BATHYMETRY > COASTAL BATHYMETRY PROVIDERS > GOVERNMENT AGENCIES-U.S. FEDERAL AGENCIES > DOI > USGS DOI/USGS/CMG/SP > ST. PETERSBURG COASTAL AND MARINE SCIENCE CENTER, COASTAL AND MARINE GEOLOGY, U.S. GEOLOGICAL SURVEY, U.S. DEPARTMENT OF THE INTERIOR USGS Thesaurus marine geology geophysics bathymetry single-beam echo sounder ocean characteristics ocean processes geospatial datasets digital elevation models hurricanes None U.S. Geological Survey hydrography trackline single-beam bathymetry Geographic Names Information System (GNIS) State of Florida Midnight Pass (historical) Gulf of America None Midnight Pass Palmer Point Park Gulf of Mexico Mid-Gulf Coast None 2025 No access constraints. Please see 'Distribution Information' for details. These data are marked with a Creative Commons CC0 1.0 Universal License. These data are in the public domain and do not have any use constraints. Nancy T. DeWitt U.S. Geological Survey, St. Petersburg Coastal and Marine Science Center Geologist mailing and physical address

600 4th Street South

St. Petersburg FL 33701-4846 USA 727-502-8000 ndewitt@usgs.gov Funding and (or) support for this study was provided as part of the coastal assessment component of the Consolidated Appropriations Act Title VII, Division N: Disaster Relief Supplemental Appropriations Act, 2023 (Public Law 117-328). The authors would like to thank members of the USGS SPCMSC Operations staff, specifically Kyle W. Kelso and Benjamin A. Galbraith for their bathymetry acquisition field support as well as Emily L. Johnson for additional field and land support. This document was improved by scientific/editorial and metadata reviews from Billy J. Reynolds and Breanna N. Williams of the SPCMSC. Environment as of Metadata Creation: Microsoft Windows 11 Enterprise Version 23H2 (Build 22631.4317); RINEX Converter version 5.1.0; Horizontal Time-Dependent Positioning (HTDP) online transformation utility version 3.5.0 (https://www.ngs.noaa.gov/TOOLS/Htdp/Htdp.shtml); NovAtel®'s Waypoint software GrafNav version 9.00.2207; HYPACK® A Xylem Brand version 23.3.4.0; Environmental Systems Research Institute (Esri) ArcGIS Pro version 3.3.2; National Oceanic and Atmospheric Administration (NOAA) and the National Geodetic Survey (NGS) VDatum software version 4.7.1 (https://vdatum.noaa.gov/). NovAtel® 202307 Alberta, Canada Novatel Inc. https://hexagondownloads.blob.core.windows.net/public/Novatel/assets/Documents/Manuals/Waypoint-Software-User-Manual-OM-20000166/Waypoint_9.00_Software_User_Manual.pdf Xylem 2023 Middletown, CT Xylem brand https://www.xylem.com/siteassets/brand/hypack/resources/manual/2023-hypack-user-manual.pdf Nina Stark Michael Gardner Michael Grilliot Andrew Lyda Karen Dedinsky Jaquelin Mueller Charli Pezoldt Johnathan Hubler Celso Castro-Bolinaga Alexander Schueller Weiwei Zhan Michael Haefeli Sarah Burghardt Maxwell Wondolowski Sam Holberg Mohamed Hassan Jack Parker Jorge Laurel-Castillo Lea Eggensberger Elliot Nichols Hanna Herndon Ping Wang Maitane Olabarrieta Lizaso Brit Raubenheimer Youssef Hashash Stephen Adusei Navid Jafari 20250130 Multidisciplinary Pre, During and Post Storm Data Collection doi:10.17603/ds2-m8h3-5802 DesignSafe-CI U.S. National Science Foundation Natural Hazards Engineering Research Infrastructure (NSF NHERI) https://doi.org/10.17603/ds2-m8h3-5802 This dataset is derived from a single survey using two vessels with identical equipment systems and acquisition settings. Prior to deployment, each vessel's equipment offsets were surveyed using a Geotronics/Spectra Precision Geodimeter 640 total station equipped with an electronic theodolite and an electronic distance meter. Offsets between the single-beam transducers, motion reference unit, and the antenna reference point (ARP) were precisely measured with respect to the vessels frame of reference. During mobilization, the offset measurements were field checked and verified against the total station measurements. Total station offsets were then digitally entered into the acquisition and (or) processing software. Methods were employed to maintain data collection consistency aboard the vessels. Differential Global Positioning System (DGPS) base station coordinates were obtained from the Florida Department of Transportation (FDOT) Florida Permanent Reference Network (FPRN) datasheets for the Continuously Operating Reference Stations (CORS) used to process the navigation data. Roving vessels remained within < 12-km of the base station. The navigation positioning data were post processed using NovAtel®'s Waypoint Software GrafNav. These data were collected during one survey with consistent instrument calibrations and consistent acquisition methods. This data release contains single-beam bathymetry data points (x,y,z) collected in June 2025 within and around Midnight Pass, Florida. The horizontal positions and vertical elevations are provided in two datums, 1) WGS84 (G2296) and ellipsoid height, and 2) NAD83(2011) NAVD88 UTM 17N GEOID18. These datasets are considered complete. Users are advised to read the complete metadata record carefully for additional details. The FDOT FPRN CORS station Sarasota Central, code name FLSS (NGS PID DR9089), was used for the local control, and the coordinate values were obtained from FPRN's FLSC datasheet (https://www.myfloridagps.com/ds/pdfs/flsc.pdf). The maximum horizontal surface vector distance from the base station to both roving vessels was 11.14 km. Horizontal positional accuracy associated with each data point was determined by post-processed differential correction of the base/rover GNSS sessions using GrafNav. Processing the full-carrier phase data allows precise positioning of the base and rover receivers. Differential processing improves the rover positions by assessing positional errors computed at the base receiver and applying those errors or differences to the rover receiver. Forward and backward time-series processing of the kinematic (rover) data provides an independent combined smoothed-trajectory solution of the baseline between the rover position and the base station. The positional accuracy can be estimated by differencing the time series (position separation). The average post-processed horizontal standard deviation accuracy (2-sigma) for all kinematic rover data processed to FLSC CORS station was 0.014 +/- 0.003 meters (m). The FDOT FPRN CORS station Sarasota Central, code name FLSC (NGS PID DR9089), was used for the local control, and the coordinate values were obtained from FPRN's FLSC datasheet. The vertical position accuracy associated with each data point was determined by post-processed differential correction of the base/rover GNSS sessions using GrafNav. The average post-processed vertical standard deviation accuracy (2-sigma) for all kinematic rover data processed to the FLSC CORS station was 0.024 +/-0.007 m. GNSS Acquisition: As reported on the FPRN FLSC CORS station datasheet, the base station was equipped with a Leica Geosystems® GR50 GNSS receiver using a Leiar20 SCIT antenna recording at a rate of 1.0 seconds (s) equal to 1 hertz (Hz). The roving vessels were each equipped with a Spectra Precision® SP90M GNSS receiver using Spectra Precision® SPGA Rover GNSS antennae recording full-carrier-phase positioning signals from satellites at a rate of 0.1 s, or 10 Hz. Post-survey, the base station data files were downloaded from the FDOT FPRN online server location in the non-proprietary Receiver Independent Exchange Format (RINEX [https://igs.org/wg/Rinex/]) format version 3.04 (e.g. FLSC17600.250). The proprietary Spectra Precision G-files (e.g. GWVR1A24.176) from the rovers were converted into RINEX format version 3.04 (e.g. WVR100000_R_20251762001_02H_10Z_MO) which converts all the satellite constellations tracked by the antenna (GPS, GLONASS, BeiDou, and Galileo). Example of the RINEX 3.04 filename is FLSC176l00.25O, where the convention FLSC is the four-letter site name, 176 is the day of year, I is the session A-Z, 00 is the time, 25 is the year, O represents the observation file, N is the navigation file, M is meteorological file, and G is the GLONASS navigation message file. Example of the RINEX 3.04 filename WVR100000_R_20251762001_02H_10Z_MO where the convention WVR100000 is the nine-letter site name, R is the data source (R - receiver), 20251762001 is the year (2025), day of year (176), and Coordinated Universal Time (UTC) start time of the file in HHMM (2001), 02H is the file time (2 hours), and the 10Z is the recording rate (10 Hz), MO is the mixed observation file, MN is the mixed navigation file, and MM is meteorological file. Spectra Precision® proprietary G-Files 2025 RINEX version 3.04 format files Nancy T. DeWitt U.S. Geological Survey Geologist mailing and physical address

600 4th Street South

St. Petersburg FL 33701-4846 USA 727-502-8000 ndewitt@usgs.gov Single-Beam Bathymetry Acquisition: A total of 47 line-km of SBES data were collected as part of FAN 2025-313-FA: the R/V Shark (WVR1 - subFAN 25BIM03) collected 24 line-km, and R/V Chum (WVR2 - subFAN 25BIM04) collected 23 line-km of data. Boat motion (heave, roll, pitch) was recorded on each vessel at 50-millisecond (ms) intervals using a SBG Systems Ellipse Series A motion sensor. HYPACK®, a marine surveying, positioning, and navigation software package, managed the planned-transect information and provided real-time navigation parameters, course corrections, data quality parameters, and instrumentation-status to the boat operator. Depth soundings were recorded at 50-ms intervals using a Teledyne® Odom Echotrac CV100 echosounder with a 4-degree, 200-kilohertz (kHz) transducer on WVR1 and WVR2. For each vessel, data from the GNSS receiver, motion sensor, and echosounder were recorded in real-time and merged into a single raw data file (.RAW) in HYPACK®, with each device string referenced by a device identification code and time stamped to UTC. Sound velocity profile (SVP) measurements were collected using SonTek® Castaway Conductivity, Temperature, and Depth (CTD) instruments. The CTD units were cast overboard to record changes in water column speed of sound (SOS) spatially and temporally. A total of 6 casts recorded sound velocities ranging from 1546.45 to 1550.33 meters per second (m/s) at water depths ranging from a minimum of -0.15 m to a maximum of -5.55 m. 2025 *.RAW, *.BIN, *.LOG,*.ctdx, *.ctd, *.csv, *.svp Nancy T. DeWitt U.S. Geological Survey Geologist mailing and physical address

600 4th Street South

St. Petersburg FL 33701-4846 USA 727-502-8000 ndewitt@usgs.gov Differentially Corrected Navigation Processing: All navigation data were acquired in WGS84 (G2296)/International Terrestrial Reference Frame of 2020 (ITRF2020). The FLSS coordinates used for post-processing the navigation collected during this survey were 27° 13' 02.19597" North, 82° 24' 17.10539" West, -16.907 m ellipsoid height, and epoch 2025.0073 obtained from the FPRN FLSC datasheet (https://www.myfloridagps.com/ds/pdfs/flsc.pdf). The rover data, base data, and the base station coordinates were imported into GrafNav (NovAtel, 2023). Each kinematic GNSS data session from the survey vessel was post-processed to the concurrent static base GNSS data session. GNSS data plots and data information generated by GrafNav including satellite health (satellite lock, satellite cycle slips), rover trajectory maps, and pre-processing logs were used to modify the processing parameters to attain trajectory solutions (between the base and the rover) that resulted in fixed positions. Primary examples include: 1) excluding satellites, flagged by GrafNav, with bad health or frequent cycle slips, 2) omitting satellite time segments that introduce positional errors which prevented a fixed solution, or 3) adjusting the satellite elevation mask angle to improve the position solutions (NovAtel, 2023). The final differentially corrected, precise DGPS positions were computed at 0.1s and exported as a single data point epochs in ASCII text format (.txt) in WGS84 (G2296) UTM Zone 17N geodetic datum. RINEX version 3.04 format files 2025 *txt Nancy T. DeWitt U.S. Geological Survey Geologist mailing and physical address

600 4th Street South

St. Petersburg FL 33701-4846 USA 727-502-8000 ndewitt@usgs.gov Single-beam Bathymetry Processing: All data were processed using HYPACK® 2023 following steps outlined in the HYPACK® 2023 User Manual (Xylem, 2023). First, the HYPACK® project geodesy settings were verified, ensuring the correct UTM Zone and "K-N from User" settings with "height of ellipsoid above chart datum" value of '0.00 were selected. Next, the .RAW data files were imported into HYPACK® Single Beam Editor (64 bit). The following "Read Parameters" were selected within the Survey Tab 'Elevation Mode' and the project information was verified. Within the Corrections Tab: the sound velocity profiles (SVP) were added as .VEL format, and 'Time and Position' was selected for the SVP interpolation method. Within the Devices Tab: the vessel offsets were added and the RTK Tides box was selected. Within the Processing Tab: 'Apply Heave Correction', 'Correct Induced Heave', 'Remove Heave Drift', 'Avoid Double Heave', 'Merge Tide Data with Heave', 'Interpolate Draft', 'Apply Pitch and Roll Corrections', and 'Steer Sounding Beam' (4 degree for the WVR1, and WVR2) were all selected. The data was then processed within HYPACK®'s Single Beam Editor (64 bit). Next, the GPS Adjustment tool was used to merge the post-processed navigation trajectory epoch solutions with their respective HYPACK® data files (.RAW). Using the Editor Profile window, these processed soundings were visually scanned for any resultant outliers which were manually removed using the editor tool. The data were then smoothed using the smoothing option with the 'number of samples for average" set to 60. Finally, the x,y,z data (easting, northing, ellipsoid height) and associated attributes (calendar date, UTC time, and line number) were exported as a single text file per line. The text files were them combined into one file per subFAN/vessel using the ArcGIS Pro's "Merge (Data Management)" geoprocessing tool, resulting in two main text files. *.RAW, *.BIN, *.LOG, *.VEL 2025 25BIM03_WVR1_PP_Merg.txt 25BIM04_WVR1_PP_Merg.txt Nancy T. DeWitt U.S. Geological Survey Geologist mailing and physical address

600 4th Street South

St. Petersburg FL 33701-4846 USA 727-502-8000 ndewitt@usgs.gov Quality Control, Quality Assurance (QA/QC) and Uncertainty Analysis: Using ArcGIS Pro, the processed single-beam datasets were then transformed into feature classes using the "Create Points From Table > XY Table to Point" geoprocessing tool and the spatial reference was set to WGS84 UTM 17N. Next, a polyline feature class (representing tracklines) was produced from the point data using XTools Pro "Make Polylines from Points" (the selection criteria being HYPACK® line name and then ordering by UTC time). Utilizing both the point and polyline feature classes, an ArcGIS Pro Python script was used to evaluate the elevation differences at the intersections of tracklines. The script does this by calculating the elevation difference between points at each intersection using an inverse distance weighting equation with a search radius of 1 m. The crossing analysis yielded a Root Mean Square Error (RMSE) of 4.00 centimeters (cm) for all crossings. When the WVR1 crossed one of its own lines, the crossing analysis yielded an RMSE of 7.1 cm. When the WVR2 crossed one of its own lines, the crossing analysis yielded an RMSE of 6.4 cm. The crossings in ArcGIS Pro were solely used as a QA/QC, not as a means of editing the data. 25BIM03_WVR1_PP_Merg.txt 25BIM04_WVR2_PP_Merg.txt 2025 Midnight_Pass_2025_SBES_WGS84_G2296_UTM17N_xyz.txt Midnight_Pass_2025_SBES_WGS84_G2296_UTM17N_Tracklines.shp Nancy T. DeWitt U.S. Geological Survey Geologist mailing and physical address

600 4th Street South

St. Petersburg FL 33701-4846 USA 727-502-8000 ndewitt@usgs.gov Datum Transformation: NOAA NGS's VDatum software was used to transform the single-beam data points' horizontal (x,y) and vertical (z) datums from WGS84 (G2269) UTM 17N (horizontal), WGS84 (G2269) ellipsoid height (vertical) using epoch year 2025.479 (start of the survey) to NAD83 UTM 17N (horizontal), NAVD88 orthometric height (vertical) using GEOID18 epoch year 2010.000. The VDatum-reported vertical uncertainty is 0.032 m. For more information about the positional accuracy for these datum transformations, visit the Estimation of Vertical Uncertainties VDatum webpage, https://vdatum.noaa.gov/docs/est_uncertainties.html. Midnight_Pass_2025_SBES_WGS84_G2296_UTM17N_xyz.txt 2025 Midnight_Pass_2025_SBES_NAD83_NAVD88_GEOID18_UTM17N_xyz.txt Nancy T. DeWitt U.S. Geological Survey Geologist mailing and physical address

600 4th Street South

St. Petersburg FL 33701-4846 USA 727-502-8000 ndewitt@usgs.gov Digital Elevation Model (DEM) Creation: Using ArcGIS Pro version 3.2.3 and the single-beam point data file (Midnight_Pass_2025_SBES_WGS84_G2296_UTM17N_xyz.txt), a 1 x 1-m cell resolution DEM was generated using ArcGIS geoprocessing tools. First, a polygon feature class was created using "Create Feature Class (Data Management)" tool and was shaped to the single-beam data file extent using ArcGIS Pro "Edit Vertices" tool. This polygon feature class was then converted to a 1 X 1-m cell size raster using the "Feature to Raster (Conversion)" tool. Second, using the single-beam point data file (Midnight_Pass_2025_SBES_WGS84_G2296_UTM17N_xyz.txt), a 1-m DEM was generated using the "Natural Neighbors" (Spatial Analyst) tool. Third, the DEM was clipped to the 1-m raster (created in the first step) using the "Extract by Mask (Spatial Analyst)" tool. The computation results produced minimum and maximum ellipsoid height values of -25.96 to -31.87, which closely resemble the single beam point data values of -25.93 to -31.88. Last, to quantify how closely the 1-m DEM represents the single-beam point data, the "Extract Values to Points (Spatial Analyst)" tool was used. This tool extracts the value from the DEM at each single-beam data point location. The 1-m DEM represented 460,721 of 462,569 data points with 1,848 (0.40%) reported as null values. Using the generated feature class and associated attribute table, the RMSE was calculated as 0.023 m. The DEM was then exported as a Geographic Tag Image File Format (GeoTIFF, .tif) file with the symbology set to stretch. Midnight_Pass_2025_SBES_WGS84_G2296_UTM17N_xyz.txt 2025 Mignight_Pass_2025_SBES_1m_DEM_WGS84_G2296_UTM17N.tif Nancy T. DeWitt U.S. Geological Survey Geologist mailing and physical address

600 4th Street South

St. Petersburg FL 33701-4846 USA 727-502-8000 ndewitt@usgs.gov Point Point 462,569 Universal Transverse Mercator 17N 0.999600 -81.000000 0.000000 500000.000000 0.000000 coordinate pair 0.6096 0.6096 meters World Geodetic System of 1984 WGS_1984 6378137.000000 298.257223563 World Geodetic System of 1984 0.01 meters Attribute values Midnight_Pass_2025_SBES_WGS84_G2296_UTM17N_xyz.txt Comma-delimited ASCII text file (.txt) containing the processed single-beam bathymetry data points from USGS FAN 2025-313-FA (subFANs 25BIM03 and 25BIM04). Data is projected to the processing datum WGS84 (G2296) UTM Zone 17N. U.S. Geological Survey X_EASTING_WGS84(G2296) x-axis coordinate, easting, WGS84 (G2139) UTM 17N. U.S. Geological Survey 349767.42 351114.99 meters Y_NORTHING_WGS84(G2296) y-axis coordinate, northing, WGS84 (G2296) UTM 17N. U.S. Geological Survey 3009858.58 3010810.41 meters ELLIPSOID_WGS84(G2296) z-value, ellipsoid height (elevation), WGS84 UTM17N. U.S. Geological Survey -31.88 -25.93 meters YEAR Day of year of data acquisition. U.S. Geological Survey 2025 2025 DOY Day of year of data acquisition. U.S. Geological Survey 176 176 DATE Day of year of data acquisition. U.S. Geological Survey 6/25/2025 6/25/2025 UTC_TIME Universe Coordinate Time (UTC) of data acquisition. U.S. Geological Survey 13:18:32.133 18:47:56.843 HH:MM:SS.sss HYPACK_LINE Identifier assigned to each HYPACK® line during acquisition. HYPACK®/U.S. Geological Survey Line name example 25BIM03_WVR1_0011_1732, where the first 7 characters are the subFAN followed by underscore (25BIM03_), the next 4 characters are the platform/vessel separated by an underscore (WVR1_), and the last 9 characters are the HYPACK® line number and start time (HHMM) in UTC separated by an underscore (0011_1732). If the same line name had multiple segments a 4-digit number was appended after the line number (for example, _0001). Midnight_Pass_2025_SBES_NAD83_NAVD88_GEOID18_UTM17N_xyz.txt Comma-delimited ASCII text file (.txt) containing the processed single-beam bathymetry data points from USGS FAN 2025-313-FA (subFANs 25BIM03 and 25BIM04). Data were transformed from its native datum to NAD83 NAVD88 UTM Zone 17 N coordinate system with respect to the GEOID 18 datum. VDatum X_EASTING_NAD83(2011) x-axis coordinate, easting, NAD83 (2011) UTM 17N. VDatum 349768.102 351115.671 meters Y_NORTHING_NAD83(2011) y-axis coordinate, northing, NAD83 (2011) UTM 17N. VDatum 3009857.986 3010809.816 meters ORTHOMETRIC_NAVD88_GEOID18 z-value, orthometric height adjusted (elevation) in NAVD88 GEOID 18. VDatum -6.164 -0.219 meters YEAR Year of data acquisition. U.S. Geological Survey 2025 2025 DOY Day of year of data acquisition. U.S. Geological Survey 176 176 Date Calendar date of data acquisition. U.S. Geological Survey 6/25/2025 6/25/2025 UTC_TIME Universe Coordinate Time (UTC) of data acquisition. U.S. Geological Survey 13:18:32.133 18:47:56.843 HH:MM:SS.sss HYPACK_LINE Identifier assigned to each HYPACK® line during acquisition. HYPACK®/U.S. Geological Survey Line name example 25BIM03_WVR1_0011_1732, where the first 7 characters are the subFAN followed by underscore (25BIM03_), the next 4 characters are the platform/vessel separated by an underscore (WVR1_), and the last 9 characters are the HYPACK® line number and start time (HHMM) in UTC separated by an underscore (0011_1732). If the same line name had multiple segments a 4-digit number was appended after the line number (for example, _0001). Midnight_Pass_2025_SBES_WGS84_G2296_tracklines.shp Polyline shapefile of the single-beam bathymetry tracklines (123 lines in total). U.S. Geological Survey FID Automatically generated feature attribute by Esri. Esri 0 122 Shape* Automatically generated feature attribute by Esri. Esri Polyline ZM Shape_Leng Length of the trackline polyline, in meters. Esri 4.55 3413.37 meters HYPACK_Lin Identifier assigned to each HYPACK® line during acquisition. HYPACK®/U.S. Geological Survey Line name example 25BIM03_WVR1_0011_1732, where the first 7 characters are the subFAN followed by underscore (25BIM03_), the next 4 characters are the platform/vessel separated by an underscore (WVR1_), and the last 9 characters are the HYPACK® line number and start time (HHMM) in UTC separated by an underscore (0011_1732). If the same line name had multiple segments a 4-digit number was appended after the line number (for example, _0001). Midnight_Pass_20125_SBES_1m_DEM_WGS84_G2296_UTM17N.tif: A 1-m cell size gridded DEM GeoTIFF (.tif) created from the x,y,z point dataset in this data release (Midnight_Pass_2025_SBES_WGS84_G2296_UTM17N_xyz.txt). The ellipsoid elevation ranges from -25.96 m to -31.87 m and is projected in WGS84 (G2296) UTM 17N. The file format is 32-bit floating point GeoTIFF with 1348 columns, 952 rows. The entity and attribute information were generated by the individual and/or agency identified as the originator of the dataset. Please review the rest of the metadata record for additional details and information. U.S. Geological Survey, St. Petersburg Coastal and Marine Science Center USGS SPCMSC Data Management mailing and physical

600 4th Street South

Saint Petersburg FL 33701 United States 727-502-8000 gs-g-spcmsc_data_inquiries@usgs.gov Midnight_Pass_2025_SBES_WGS84_G2296_UTM17N_xyz.txt, Midnight_Pass_2025_SBES_NAD83_NAVD88_GEOID18_UTM167N_xyz.txt, Midnight_Pass_20125_SBES_1m_DEM_WGS84_G2296_UTM17N.tif, Midnight_Pass_2025_WGS84_G2296_UTM17N_tracklines.shp, Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data for other purposes, nor on all computer systems, nor shall the act of distribution constitute any such warranty. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. comma-delimited text, shapefile ZIP https://coastal.er.usgs.gov/data-release/doi-P13I93P7/data/Midnight_Pass_2025_SBES_WGS84_G2296_UTM17N_xyz.zip https://coastal.er.usgs.gov/data-release/doi-P13I93P7/data/Midnight_Pass_2025_SBES_NAD83_NAVD88_GEOID18_UTM17N_xyz.zip https://coastal.er.usgs.gov/data-release/doi-P13I93P7/data/Midnight_Pass_2025_WGS84_G2296_tracklines.zip https://coastal.er.usgs.gov/data-release/doi-P13I93P7/data/Midnight_Pass_20125_SBES_1m_DEM_WGS84_G2296_UTM17N.zip None 20260424 U.S. Geological Survey, St. Petersburg Coastal and Marine Science Center USGS SPCMSC Data Management mailing and physical

600 4th Street South

Saint Petersburg FL 33701 United States 727-502-8000 gs-g-spcmsc_data_inquiries@usgs.gov Content Standard for Digital Geospatial Metadata FGDC-STD-001-1998