OPR-A325-KR-24 Boston and Gloucester, MA Northern Massachusetts Bay Ocean Surveys H13992 2 Salem Harbor Massachusetts United States 5000 2025 John R. Bean Navigable Area 2024-08-01 2024-08-14 2025-03-14 Multibeam Echo Sounder Multibeam Echo Sounder Backscatter meters UTC Atlantic Hydrographic Branch Any revisions to the Descriptive Report (DR) applied during office processing are shown in red italic text. The DR is maintained as a field unit product, therefore all information and recommendations within this report are considered preliminary unless otherwise noted. The final disposition of survey data is represented in the NOAA nautical chart products. All pertinent records for this survey are archived at the National Centers for Environmental Information (NCEI) and can be retrieved via https://www.ncei.noaa.gov/. Products created during office processing were generated in NAD83 UTM 19N, MLLW. All references to other horizontal or vertical datums in this report are applicable to the processed hydrographic data provided by the field unit. CC0-1.0 (NOAA Contractors) CC0-1.0 https://creativecommons.org/publicdomain/zero/1.0/ https://creativecommons.org/publicdomain/zero/1.0/legalcode These data were produced under contract with NOAA and any potential copyright was assigned to NOAA. NOAA waives any potential copyright and related rights in these data worldwide through the Creative Commons Zero 1.0 Universal Public Domain Dedication (CC0). Contractor This survey provides hydrographic data for waters in Northern Massachusetts Bay. The general locations of the survey limits are presented in Table 1. 42.574511111111114 70.9139138888889 42.444513888888885 70.69891944444444 Survey limits were acquired in accordance with the requirements in the Project Instructions and the HSSD. The waters in and around the ports of Boston and Gloucester in Northern Massachusetts Bay are some of the most heavily used in the US by commercial and recreational boating traffic. The Port of Boston sees more than 16 million tons of cargo movement annually*, and thousands of vessels travel into, out of, and within Boston Harbor every year. Boston, Gloucester and Rockport are also major fishing ports, with average yearly landings of over 40 million pounds worth over $80 million**. This project will also provide an analysis of the feasibility of using inshore bathymetric lidar data for identifying and updating features, in concert with new multibeam sonar data collection. The prior survey data in much of the survey area is over 20 years old, and several areas have data that is from the 1940s. The survey area has an extensive coastline, and has been heavily trafficked by humans for almost 400 years; there have been extensive and poorly documented effects and changes to the seafloor by human activity***. This survey will address this by collecting modern high resolution bathymetry for updating NOAA nautical charting products improving the safety of maritime traffic and commerce as well as supporting the Seabed 2030 global mapping initiative. Survey data from this project is intended to supersede all prior survey data in the common area. *Massachusetts Port Authority Statistics 2022 **2022 NMFS Landing Statistics https://www.fisheries.noaa.gov/national/sustainable-fisheries/commercial-fisheries-landings ***https://www.sec.state.ma.us/divisions/cis/historical/historical-sketch.htm and https://stellwagen.noaa.gov/maritime/maritimehistory.html The entire survey is adequate to supersede previous data. All waters in survey area within ACHARE feature in PRF Object Detection Coverage (Refer to HSSD Section 5.2.2.2) All Other Waters in Survey Area Complete Coverage (Refer to HSSD Section 5.2.2.3) Survey coverage was in accordance with the requirements listed above and in the HSSD. Project OPR-A325-KR-24 coverage with H13992 emphasized. file:///B:/OPR-A325-KR-24/Surveys/H13992/01_HDR/Reports/Descriptive_Report/SupportFiles/H13392-Overview.jpg RV South Cove 0.0 835.0 0.0 0.0 0.0 0.0 0.0 69.8 0.0 RV Twister 0.0 11.2 0.0 0.0 0.0 0.0 0.0 0.0 0.0 RV West Cove II 0.0 695.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1541.2 0.0 0.0 0.0 0.0 0.0 69.8 0.0 4.5 0 0 0 0 25.6 2024-08-14 2024-08-15 2024-08-16 2024-08-17 2024-08-18 2024-08-19 2024-08-20 2024-08-21 2024-08-22 2024-08-23 2024-08-24 2024-08-25 2020-08-26 2024-08-27 2024-08-28 2024-08-29 2024-08-30 2024-09-04 2024-09-05 2024-09-06 2024-09-07 2024-11-20 2024-11-21 2024-11-22 2024-11-23 2025-03-12 2025-03-13 2025-03-14 Refer to the Data Acquisition and Processing Report (DAPR) for a complete description of data acquisition and processing systems, survey vessels, quality control procedures and data processing methods. Additional information to supplement sounding and survey data, and any deviations from the DAPR, are discussed in the following sections. RV South Cove 9.4 0.8 RV Twister 9.4 0.8 RV West Cove II 12.8 1.4 RV South Cove configured for survey operations. file:///B:/OPR-A325-KR-24/Surveys/H13992/01_HDR/Reports/Descriptive_Report/SupportFiles/SC-overview.jpg RV Twister configured for survey operations. file:///B:/OPR-A325-KR-24/Surveys/H13992/01_HDR/Reports/Descriptive_Report/SupportFiles/TW-overview.jpg RV West Cove II configured for survey operations. file:///B:/OPR-A325-KR-24/Surveys/H13992/01_HDR/Reports/Descriptive_Report/SupportFiles/WC-overview.jpg MBES Teledyne RESON SeaBat T50-R Positioning and Attitude System Applanix POS MV 320 v5 Positioning System Trimble NetR9 Sound Speed System AML Oceanographic Micro SV-Xchange Conductivity, Temperature, and Depth Sensor AML Oceanographic AML-3 LGR Lidar System Velodyne LiDAR VLP-16 Crossline mileage in H13992 totaled 4.5% of the mainscheme survey miles. Agreement between crosslines and mainscheme bathymetry was very good, with a mean difference of 0.01m in the 50cm resolution surface. Crossline tracks overlaid on a coverage surface. file:///B:/OPR-A325-KR-24/Surveys/H13992/01_HDR/Reports/Descriptive_Report/SupportFiles/H13392-XL.jpg Depth differences between mainscheme and crossline data. file:///B:/OPR-A325-KR-24/Surveys/H13992/01_HDR/Reports/Descriptive_Report/SupportFiles/H13992_MB_50cm_Main-H13992_MB_50cm_XL_depth_delta.png ERS via VDATUM 0.13 RV South Cove 4 2 RV Twister 4 2 RV West Cove II 4 2 The NOAA Pydro QC Tools application was used to calculate TVU QC, determined by a ratio of uncertainty to the allowable error per NOAA and IHO specification. A set of surfaces was finalized in CARIS HIPS using the "uncertainty" option to select the combination of a priori and realtime uncertainty estimates as the surface TVU source. The surfaces represented areas of object detection coverage or complete multibeam coverage at different resolutions as appropriate for the water depths, and all surfaces passed the uncertainty check, with at least 98% of nodes meeting the uncertainty standards. Histograms are shown for the 50cm object detection coverage and the 2m complete coverage surface, which were the resolutions that covered the largest survey area for their respective coverage types. Uncertainty standards, 50cm object detection coverage. file:///B:/OPR-A325-KR-24/Surveys/H13992/01_HDR/Reports/Descriptive_Report/SupportFiles/H13992_MB_50cm_MLLW_Final_1of4.GQv6.tvu_qc.png Uncertainty standards, 2m complete coverage. file:///B:/OPR-A325-KR-24/Surveys/H13992/01_HDR/Reports/Descriptive_Report/SupportFiles/H13992_MB_2m_MLLW_Final_4of4.GQv6.tvu_qc.png Junction analysis was assigned for a lidar survey that was under review at the time of the PI, and contemporary surveys junction with the northeastern, southeastern, and southwestern edges of H13992. H13992 junction map with junction area depth differences. file:///B:/OPR-A325-KR-24/Surveys/H13992/01_HDR/Reports/Descriptive_Report/SupportFiles/H13392-Junction.jpg MA2204 1 2021 NOAA RSD N Preliminary lidar data were provided to OSI and used to perform the junction analysis. Data from MA2204 junctions with the inshore western areas of H13992. Agreement between the two surveys was good, with a mean difference of 0.11m. Areas of flat bathymetry had the best agreement, where rocky areas showed greater differences. Differences were also seen in cases where OSI surveyed bathymetry beneath docks or piers and the lidar elevation represented the top of these structures. Depth differences between H13992 and MA2204. file:///B:/OPR-A325-KR-24/Surveys/H13992/01_HDR/Reports/Descriptive_Report/SupportFiles/H13992_MB_1m_MLLW-MA2204_1m_dem_tpu_MLLW_depth_delta.png H13991 5000 2025 OSI NE The northeast edge of H13992 abuts H13991, with a shared border of approximately 3.3 km. The northern end of the junction area is in the rocky area surrounding Kettle Island and shows greater depth differences on the rocks, and depth differences were also more pronounced at the trackline edges in outer beam data. Agreement between the two surveys was still good, with a mean difference of 0.07m. Depth differences between H13991 and H13992. file:///B:/OPR-A325-KR-24/Surveys/H13992/01_HDR/Reports/Descriptive_Report/SupportFiles/H13991_MB_1m_MLLW-H13992_MB_1m_MLLW_depth_delta.png H13993 5000 2024 OSI SE The long southeastern edge of H13992 junctions with H13993, with a shared border of approximately 17.6 km. The junction area covers several rocky areas and ledges, where depth discrepancies were higher, and outer beam data in the deeper waters also showed greater differences between the two surveys. However most of the junction had good agreement, with an average depth difference of 0.03m. Depth differences between H13992 and H13993. file:///B:/OPR-A325-KR-24/Surveys/H13992/01_HDR/Reports/Descriptive_Report/SupportFiles/H13992_MB_1m_MLLW-H13993_MB_1m_MLLW_depth_delta.png H13996 5000 2025 OSI SW The southwest edge of H13992 junctions with H13996, with a shared border of approximately 2.7 km. Depth differences were greatest at the northern end of the boundary, near the rocky coast. Agreement between the two surveys was very good, with a mean difference of 0.04m. Depth differences between H13992 and H13996. file:///B:/OPR-A325-KR-24/Surveys/H13992/01_HDR/Reports/Descriptive_Report/SupportFiles/H13992_MB_1m_MLLW-H13996_MB_1m_MLLW_depth_delta.png Sonar system quality control checks were conducted as detailed in the quality control section of the DAPR. None Exist There were no conditions or deficiencies that affected equipment operational effectiveness. Sound Speed Variation Sound speed variations were observed throughout the survey area, correlating to factors including the tide, weather, water depth, and bathymetric features, such as slopes or sand waves. In data processing, sound speed profiles that did not adequately reflect the surrounding water mass were identified and removed, edited, or replaced. Sound speed casts were primarily applied using the CARIS HIPS "Nearest in Distance within Time" method, therefore, removing a profile collected on a steep slope would allow deeper and shoaler casts on either side to be applied instead. Casts that were empirically found to represent a large water zone were added at additional locations within that zone to ensure proper corrections given the cast selection options available in the CARIS sound speed tools. Bathymetry, uncertainty, and standard deviation surfaces were used to direct editing and determine the accuracy of sound speed cast selection. RV South Cove and RV West Cove II acquired AML3 casts at intervals of approximately 60 minutes, and RV Twister acquired AML3 casts at intervals of approximately 40 minutes. Hydrographers acquired more frequent sound speed profiles if high variability was noted in the surface sound speed from the AML Micro-X installed on the head of the transducer, or when the surface sound speed comparison threshold was exceeded (>2m/s change) between the profile reading at the draft of the transducer and the Micro-X. OSI submitted a data package titled "SOUND VELOCITY collected from MV Northstar Challenger, RV North Cove, RV South Cove, RV Twister, and RV West Cove II in North Atlantic Ocean, Northern Massachusetts Bay from 2024-08-03 to 2025-03-28" in NetCDF format to the National Centers for Environmental Information (NCEI) on May 5, 2025. H13992 Sound speed cast locations. file:///B:/OPR-A325-KR-24/Surveys/H13992/01_HDR/Reports/Descriptive_Report/SupportFiles/H13392-SVP.jpg The majority of this survey was conducted to achieve Object Detection Coverage with multibeam, as specified in HSSD 5.2.2.2, Option A. Portions of the survey outside the assigned Object Detection areas as defined in the PRF were instead conducted to achieve Complete Coverage with multibeam, as specified in HSSD 5.2.2.3, Option A. The survey methods used to meet coverage requirements did not deviate from those described in the DAPR. Object Detection holidays are present in the 50cm resolution surface, primarily in crevices of rocky areas or on the sides of individual rocks. In one such case, the top of the rock was not captured and was not investigated further for the sake of survey vessel safety. No other holidays are present over the tops of features or other areas of potential navigational significance. The NOAA Pydro QC Tools application was used to verify that the multibeam data met the density coverage requirements for each of the finalized grids submitted for the survey. All surfaces passed the density check, which requires 95% of nodes to be populated with at least 5 soundings. Histograms are shown for the 50cm object detection coverage and the 2m complete coverage surface, which were the resolutions that covered the largest survey area for their respective coverage types. Data density, 50cm resolution object detection coverage. file:///B:/OPR-A325-KR-24/Surveys/H13992/01_HDR/Reports/Descriptive_Report/SupportFiles/H13992_MB_50cm_MLLW_Final_1of4.GQv6.density.png Data density, 2m resolution complete coverage. file:///B:/OPR-A325-KR-24/Surveys/H13992/01_HDR/Reports/Descriptive_Report/SupportFiles/H13992_MB_2m_MLLW_Final_4of4.GQv6.density.png All data reduction procedures conform to those detailed in the DAPR. All sounding systems were calibrated as detailed in the DAPR. All equipment and survey methods were used as detailed in the DAPR. H13992 multibeam backscatter mosaic. file:///B:/OPR-A325-KR-24/Surveys/H13992/01_HDR/Reports/Descriptive_Report/SupportFiles/H13392-Backscatter.jpg NOAA Profile Version 2024 H13992_MB_50cm_MLLW_Final_1of4 CARIS Raster Surface (CUBE) 0.5 -1.8 20.0 NOAA_0.5m Object Detection H13992_MB_1m_MLLW_Final_2of4 CARIS Raster Surface (CUBE) 1 18.0 35.6 NOAA_1m Object Detection H13992_MB_1m_MLLW_Final_3of4 CARIS Raster Surface (CUBE) 1 1.0 20.0 NOAA_1m Complete MBES H13992_MB_2m_MLLW_Final_4of4 CARIS Raster Surface (CUBE) 2 18.0 43.9 NOAA_2m Complete MBES H13992_MB_50cm_MLLW_1of3 CARIS Raster Surface (CUBE) 0.5 -1.8 44.0 NOAA_0.5m Source H13992_MB_1m_MLLW_2of3 CARIS Raster Surface (CUBE) 1 -1.7 44.0 NOAA_1m Source H13992_MB_2m_MLLW_3of3 CARIS Raster Surface (CUBE) 2 -1.7 43.9 NOAA_2m Source H13992_MBAB_2m_400kHz_1of1 MB Backscatter Mosaic 2 N/A Processed Backscatter The unfinalized csar surfaces are sources containing both object detection and complete coverage areas. After finalization in CARIS, the surfaces were modified using the CARIS coverage extraction tool to clip their boundaries such that they include the appropriate object detection or complete coverage areas only. The finalized surfaces are numbered 1-4, with object detection coverage listed first (1of4, 2of4) followed by complete coverage surfaces (3of4, 4of4). The CARIS files delineating the different coverage areas that were used for the extraction are included in Supporting Data. Although the surveyed depths in the 2m resolution complete coverage surface exceed the maximum depth limit of 40m for that resolution, an additional surface of 4m resolution for the deepest area was not included. The total area deeper than 40m was less than 1% of the survey area and the data density of the 2m resolution surface in this area passed the density check, with 99.5% of the grid nodes populated by at least 5 soundings. Data density, 2m resolution surface of areas deeper than 40m. file:///B:/OPR-A325-KR-24/Surveys/H13992/01_HDR/Reports/Descriptive_Report/SupportFiles/H13992_MB_2m_MLLW_Final_deeper-than-40m.GQv6.density.png Additional information discussing the vertical or horizontal control for this survey can be found in the accompanying HVCR. Mean Lower Low Water ERS via VDATUM OPR-A325-KR-24_NAD83(2011)-MHW.csar OPR-A325-KR-24_NAD83(2011)-MLLW.csar North American Datum 1983 (2011) Projected UTM 19 Smart Base Single Base Milton MAMI Plymouth MAPL Salisbury MASA Tewksbury MATB Truro MATU Wrentham MAWR Gorham MEGO Rockland MERO U New Hampshire NHUN Westford WES2 Boston WAAS 1 ZBW1 Ocean Surveys Gloucester OSGL US5BOSDF 22000 3 2025-02-25 2025-02-25 US5MA1RG 12000 3 2025-02-28 2025-02-28 US5MA1RH 12000 4 2025-02-28 2025-02-28 US5MA1RI 22000 3 2025-02-28 2025-02-28 US5MA1SG 12000 5 2025-03-21 2025-03-21 US5MA1SH 12000 4 2025-03-21 2025-03-21 US5MA1SI 12000 3 2025-03-04 2025-03-04 US5MA1SJ 12000 3 2025-03-04 2025-03-04 DTON reports were submitted for 3 shoal rocks, and no other potential hazardous features were found. Charted features assigned in H13992 included items that were inshore of NALL or outside the defined survey coverage limits for the vessels on this project. To address these features, OSI undertook an additional task of lidar evaluation as outlined in the PI. Lidar data from survey MA2204, including both a grid and point cloud data, were provided to OSI to use for this additional analysis. Two separate feature files were submitted for this survey; a standard FFF file including features addressed with OSI survey data, and a separate Lidar Final Feature File (LI_FFF) for features addressed using the provided lidar data. Features addressed using OSI survey data and documented in the FFF were primarily submerged rocks and obstructions. Some of the assigned docks were within range of vessel-mounted lidar and so were also addressed with OSI survey data. Features documented in the LI_FFF were primarily rocks, seabed areas of rock, land areas, obstructions, and docks. The only uncharted submerged feature surveyed in H13992 was an obstruction, found in the search radius of a charted wreck that was not present. Other new features in the FFF consist mostly of repositioned features for charted named rocks and for the rocks submitted as DTONS. The Salem Harbor 32-Foot Channel was surveyed, as was a portion of the Salem Harbor 10-Foot South River Channel. All areas covered by survey data were at or below their charted depths. Marblehead Harbor Fairway is charted as being marked with a series of buoys, which were not present at the time of survey. These absent buoys were reported to the U.S. Coast Guard. All other charted ATONS within the survey area were found at or near their charted positions. No Maritime Boundary Points were assigned for this survey. No bottom samples were required for this survey. Bridges and overhead cables are present in the survey and were found to be accurately represented on the charts. The Algonquin Gas Transmission Pipeline crosses the survey area, with one end at the shoreline in Salem and the other continuing off the eastern border of the sheet. The path of the pipeline can be seen at several places in the multibeam data as a mound or trench, but the actual pipeline was not elevated or exposed. There are also 3 sewer pipelines within the survey data, 1 terminating in Manchester Bay and 2 crossing Salem Harbor. The path across Salem Harbor is visible as a trench, but no exposed pipelines were surveyed. No platforms exist for this survey. A seasonal ferry between Boston and Salem may pass through this survey area, but the route is not on the chart. No abnormal seafloor or environmental conditions exist for this survey. No present or planned construction or dredging exist within the survey limits. No new surveys or further investigations are recommended for this area. No new ENC scales are recommended for this area. As Chief of Party, field operations for this hydrographic survey were conducted under my direct supervision, with frequent personal checks of progress and adequacy. I have reviewed the attached survey data and reports. All field sheets, this Descriptive Report, and all accompanying records and data are approved. All records are forwarded for final review and processing to the Processing Branch. The survey data meets or exceeds requirements as set forth in the NOS Hydrographic Surveys Specifications and Deliverables, Field Procedures Manual, Letter Instructions, and all HSD Technical Directives. These data are adequate to supersede charted data in their common areas. This survey is complete and no additional work is required with the exception of deficiencies noted in the Descriptive Report. John R. Bean Chief of Party 2025-06-05 David T. Somers Data Processing Manager 2025-06-05