OPR-A325-KR-24 Boston and Gloucester, MA Northern Massachusetts Bay Ocean Surveys H13994 5 Central Approaches to Boston Harbor Massachusetts United States 5000 2025 John R. Bean Navigable Area 2024-08-01 2024-09-10 2025-03-15 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. 42.385758333333335 70.94266666666667 42.268855555555554 70.83514166666666 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) Survey coverage was in accordance with the requirements listed above and in the HSSD. Project OPR-A325-KR-24 coverage with H13994 emphasized. file:///B:/OPR-A325-KR-24/Surveys/H13994/01_HDR/Reports/Descriptive_Report/SupportFiles/H13394-Overview.jpg MV Northstar Challenger 0.0 285.5 0.0 0.0 0.0 0.0 0.0 0.0 0.0 RV North Cove 0.0 118.9 0.0 0.0 0.0 0.0 0.0 0.0 0.0 RV South Cove 0.0 425.2 0.0 0.0 0.0 0.0 0.0 43.3 0.0 RV West Cove II 0.0 112.4 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 942.0 0.0 0.0 0.0 0.0 0.0 43.3 0.0 4.6 0 0 0 0 12.6 2024-09-10 2024-09-11 2024-09-12 2024-09-14 2024-09-15 2024-09-16 2024-09-17 2024-09-18 2024-09-27 2024-09-28 2024-09-29 2024-09-30 2024-10-01 2024-10-02 2024-10-03 2024-10-04 2024-10-05 2024-10-06 2024-10-09 2025-03-15 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. MV Northstar Challenger 28.0 2.6 RV North Cove 11.1 0.8 RV South Cove 9.4 0.8 RV West Cove II 12.8 1.4 MV Northstar Challenger configured for survey operations. file:///B:/OPR-A325-KR-24/Surveys/H13994/01_HDR/Reports/Descriptive_Report/SupportFiles/CH-overview.jpg RV North Cove configured for survey operations. file:///B:/OPR-A325-KR-24/Surveys/H13994/01_HDR/Reports/Descriptive_Report/SupportFiles/NC-overview.jpg RV South Cove configured for survey operations. file:///B:/OPR-A325-KR-24/Surveys/H13994/01_HDR/Reports/Descriptive_Report/SupportFiles/SC-overview.jpg RV West Cove II configured for survey operations. file:///B:/OPR-A325-KR-24/Surveys/H13994/01_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 MVP30-350 Conductivity, Temperature, and Depth Sensor AML Oceanographic AML-3 LGR Lidar System Velodyne LiDAR VLP-16 Crossline mileage in H13994 totaled 4.6% of the mainscheme survey miles. Agreement between crosslines and mainscheme bathymetry was very good, with a mean difference of 0.0m in the 50cm resolution surface. Crossline tracks overlaid on a coverage surface. file:///B:/OPR-A325-KR-24/Surveys/H13994/01_HDR/Reports/Descriptive_Report/SupportFiles/H13394-XL.jpg Depth differences between mainscheme and crossline data. file:///B:/OPR-A325-KR-24/Surveys/H13994/01_HDR/Reports/Descriptive_Report/SupportFiles/H13994_MB_50cm_Main-H13994_MB_50cm_XL_depth_delta.png ERS via VDATUM 0.13 MV Northstar Challenger 4 2 RV North Cove 4 2 RV South Cove 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 different resolutions as appropriate for the water depths. Both surfaces passed the uncertainty check, with 99.5+% of nodes meeting the uncertainty standards. Uncertainty standards, 50cm resolution surface. file:///B:/OPR-A325-KR-24/Surveys/H13994/01_HDR/Reports/Descriptive_Report/SupportFiles/H13994_MB_50cm_MLLW_Final_1of2.GQv6.tvu_qc.png Uncertainty standards, 1m resolution surface. file:///B:/OPR-A325-KR-24/Surveys/H13994/01_HDR/Reports/Descriptive_Report/SupportFiles/H13994_MB_1m_MLLW_Final_2of2.GQv6.tvu_qc.png H13995 junctions with contemporary surveys on its western, northern, northeastern, and eastern edges. The northern and western boundaries are buffered by unassigned channels between the surveys, so the area of data overlap is reduced. Junction analyses were also assigned for LiDAR surveys that were under review at the time of the PI. H13990 5000 2025 OSI W This junction is addressed in the H13990 DR. H13995 5000 2025 OSI NE Survey H13995 junctions with the northwest border of H13994, with a shared border of approximately 10.2km in length. Agreement between the two surveys is very good, with a mean depth difference of 0.02m. Variation was greatest in the rockier areas between the two surveys, particularly in the northern third of the junction area where the bathymetry is characterized by large rock outcroppings. Depth differences between surveys H13994 and H13995, 1m resolution surface. file:///B:/OPR-A325-KR-24/Surveys/H13994/01_HDR/Reports/Descriptive_Report/SupportFiles/H13994_MB_1m_MLLW-H13995_MB_1m_MLLW_depth_delta.png H13996 5000 2025 OSI N This junction is addressed in the H13996 DR. H13997 5000 2025 OSI E Survey H13997 junctions with the eastern border of H13994, with a shared border of approximately 3.7km in length. Agreement between the two surveys is very good, with a mean depth difference of 0.01m. Depth differences between surveys H13994 and H13997, 1m resolution surface. file:///B:/OPR-A325-KR-24/Surveys/H13994/01_HDR/Reports/Descriptive_Report/SupportFiles/H13994_MB_1m_MLLW-H13997_MB_1m_MLLW_depth_delta.png H13994 junction map with junction area depth differences. file:///B:/OPR-A325-KR-24/Surveys/H13994/01_HDR/Reports/Descriptive_Report/SupportFiles/H13394-Junction.jpg 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. MV Northstar Challenger acquired MVP casts at intervals of approximately 20 minutes. An AML-3 LGR was also onboard the MV Northstar Challenger and used when the presence of fixed fishing gear precluded the use of the MVP. AML casts were acquired at approximately 2-hour intervals. RV North Cove, RV South Cove, and RV West Cove II all acquired AML3 casts at intervals of approximately 60 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. H13994 Sound speed cast locations. file:///B:/OPR-A325-KR-24/Surveys/H13994/01_HDR/Reports/Descriptive_Report/SupportFiles/H13394-SVP.jpg This survey was conducted to achieve Object Detection Coverage with multibeam, as specified in HSSD 5.2.2.2, Option A. The survey methods used to meet coverage requirements did not deviate from those described in the DAPR. 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. Both surfaces passed the density check, which requires 95% of nodes to be populated with at least 5 soundings. Coverage holidays are present in the 50cm resolution surface, primarily in crevices of rocky areas or on the sides of individual rocks. No holidays are present over the tops of features or other areas of potential significance. Data density, 50cm resolution surface. file:///B:/OPR-A325-KR-24/Surveys/H13994/01_HDR/Reports/Descriptive_Report/SupportFiles/H13994_MB_50cm_MLLW_Final_1of2.GQv6.density.png Data density, 1m resolution surface. file:///B:/OPR-A325-KR-24/Surveys/H13994/01_HDR/Reports/Descriptive_Report/SupportFiles/H13994_MB_1m_MLLW_Final_2of2.GQv6.density.png Holidays in 50cm resolution object detection surface. file:///B:/OPR-A325-KR-24/Surveys/H13994/01_HDR/Reports/Descriptive_Report/SupportFiles/OD-Holiday.jpg 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. H13994 multibeam backscatter mosaic. file:///B:/OPR-A325-KR-24/Surveys/H13994/01_HDR/Reports/Descriptive_Report/SupportFiles/H13394-Backscatter.jpg NOAA Profile Version 2024 H13994_MB_50cm_MLLW_Final_1of2 CARIS Raster Surface (CUBE) 0.5 -1.2 20.0 NOAA_0.5m Object Detection H13994_MB_1m_MLLW_Final_2of2 CARIS Raster Surface (CUBE) 1 18.0 29.9 NOAA_1m Object Detection H13994_MB_50cm_MLLW_1of2 CARIS Raster Surface (CUBE) 0.5 -1.2 29.9 NOAA_0.5m Source H13994_MB_1m_MLLW_2of2 CARIS Raster Surface (CUBE) 1 -1.2 29.9 NOAA_1m Source H13994_MBAB_2m_400kHz_1of1 MB Backscatter Mosaic 2 N/A Processed Backscatter 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 Wrenthm MAWR Machias MEMA U New Hampshire NHUN U of RI Coop URIL Westford WES2 Boston WAAS 1 ZBW1 Ocean Surveys Gloucester OSGL US5BOSBF 22000 3 2025-02-19 2025-02-19 US5BOSCE 22000 4 2025-02-19 2025-02-19 US5BOSCF 22000 4 2025-02-19 2025-02-19 US5BOSDE 22000 3 2025-02-25 2025-02-25 This survey had 10 DTONS submitted representing groups of shoal rocks or areas of rock outcrops that were not adequately charted. In several cases the previous RNC charts had soundings for these DTONS, but they had been removed from the ENC and the ENC contours did not adequately reflect surveyed bathymetry. A majority of the charted features assigned in H13994 were rocks, most of which were present and adequately represented in the bathymetry grid. Halftide Rock and Tewksbury Rock were the only named rocks within the survey, and a new feature was included in the FFF representing the surveyed shoal point of Halftide Rock. The surveyed shoal point of Tewksbury Rock is within the junction of this survey and adjacent survey H13995, and it is included only in the H13995 FFF. All 9 charted wrecks were found to be present and larger than 1mm at survey scale, and so included in the FFF as new area features. A charted obstruction located in the Boston Harbor Main Ship Channel was similarly large and is included as a new obstruction area feature. Of the other charted obstructions, 2 were found to be rocks/rocky areas and 1 already charted as an area was found to be slightly larger than charted. See the FFF for details. Most of the uncharted features in H13994 were wrecks or obstructions found near wrecks. A charted mooring buoy was not present but there were 3 mounds on the seafloor near its position, the tallest of these is included as a new obstruction feature. New features are also included for the potentially hazardous rocks that were surveyed. See the FFF for details. No channels exist within the survey limits. There were 27 ATONS observed in or near survey H13994, all of which were at or near their charted positions. No uncharted aids were observed, and no reports were made to the U.S. Coast Guard. No Maritime Boundary Points were assigned for this survey. No bottom samples were required for this survey. No overhead features exist for this survey. An outfall pipe crosses the northern end of H13994, and was not elevated or exposed within this survey. A major gas pipeline also crosses H13994, and while its path is visible in the multibeam data no actual pipeline was exposed. No platforms exist for this survey. Seasonal ferries from Boston to Salem or Provincetown may cross through this survey, but the routes are 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