OPR-A325-KR-24 Boston and Gloucester, MA Northern Massachusetts Bay Ocean Surveys H13990 4 Boston Harbor Massachusetts United States 5000 2025 John R. Bean Navigable Area 2024-08-01 2024-09-25 2025-03-28 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. 42.39924444444444 71.0805361111111 42.23558888888889 70.85823888888888 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 H13990 emphasized. file:///B:/OPR-A325-KR-24/Surveys/H13990/01_HDR/Reports/Descriptive_Report/SupportFiles/H13390-Overview.jpg RV North Cove 0.0 749.3 0.0 0.0 0.0 0.0 0.0 19.3 0.0 RV South Cove 0.0 1268.2 0.0 0.0 0.0 0.0 0.0 82.8 0.0 0.0 2017.5 0.0 0.0 0.0 0.0 0.0 102.1 0.0 5.1 0 0 0 0 16.5 2024-09-25 2024-09-26 2024-10-01 2024-10-03 2024-10-04 2024-10-06 2024-10-07 2024-10-08 2024-10-09 2024-10-10 2024-10-11 2024-10-13 2024-10-14 2024-10-15 2024-10-16 2024-10-17 2024-10-18 2024-10-19 2024-10-20 2024-10-21 2024-10-22 2024-10-23 2024-10-24 2024-10-25 2024-10-26 2024-10-27 2024-10-28 2024-10-29 2024-10-30 2024-10-31 2024-11-01 2024-11-02 2024-11-03 2024-11-04 2024-11-05 2024-11-06 2024-11-07 2024-11-08 2024-11-10 2024-11-11 2024-11-13 2024-11-14 2024-11-15 2024-11-16 2024-11-17 2024-11-18 2024-11-19 2025-03-16 2025-03-17 2025-03-18 2025-03-19 2025-03-20 2025-03-24 2025-03-25 2025-03-26 2025-03-27 2025-03-28 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 North Cove 11.1 0.8 RV South Cove 9.4 0.8 RV North Cove configured for survey operations. file:///B:/OPR-A325-KR-24/Surveys/H13990/01_HDR/Reports/Descriptive_Report/SupportFiles/NC-overview.jpg RV South Cove configured for survey operations. file:///B:/OPR-A325-KR-24/Surveys/H13990/01_HDR/Reports/Descriptive_Report/SupportFiles/SC-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 H13990 totaled 5.1% 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/H13990/01_HDR/Reports/Descriptive_Report/SupportFiles/H13390-XL.jpg Depth differences between mainscheme and crossline data. file:///B:/OPR-A325-KR-24/Surveys/H13990/01_HDR/Reports/Descriptive_Report/SupportFiles/H13990_MB_50cm_Main-H13990_MB_50cm_XL_depth_delta.png ERS via VDATUM 0.13 RV North Cove 4 2 RV South Cove 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 pair 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 at different resolutions as appropriate for the water depths; graphs are shown for both surfaces. All surfaces passed the uncertainty check, with 96% and 99.5+% of nodes meeting the uncertainty standards. Uncertainty standards, 50cm resolution surface. file:///B:/OPR-A325-KR-24/Surveys/H13990/01_HDR/Reports/Descriptive_Report/SupportFiles/H13990_MB_50cm_MLLW_Final_1of2.GQv6.tvu_qc.png Uncertainty standards,1m resolution surface. file:///B:/OPR-A325-KR-24/Surveys/H13990/01_HDR/Reports/Descriptive_Report/SupportFiles/H13990_MB_1m_MLLW_Final_2of2.GQv6.tvu_qc.png H13990 junctions with contemporary surveys H13994 and H13996 at its eastern end. A lidar junction assigned in the PI was contingent upon availability of the survey, which was undergoing review at the time of the PI; however, it was not available in time for use as a junction comparison for this DR. H13990 junction map with junction area depth differences. file:///B:/OPR-A325-KR-24/Surveys/H13990/01_HDR/Reports/Descriptive_Report/SupportFiles/H13390-Junction.jpg H13994 5000 2025 OSI E Part of the area between surveys H13990 and H13994 is buffered by an unassigned channel, so the area of data overlap is reduced to a 1.5km long border to the south of this channel. There is also a small section of overlap where a search radius for a disproved feature in H13990 extended across the unassigned channel and into H13994; this area is approximately 100m by 200m. Agreement between the two surveys was very good, with a mean difference of 0.02m. Depth differences between surveys H13990 and H13994. file:///B:/OPR-A325-KR-24/Surveys/H13990/01_HDR/Reports/Descriptive_Report/SupportFiles/H13990_MB_50cm_MLLW-H13994_MB_50cm_MLLW_depth_delta.png H13996 5000 2025 OSI E The junction between surveys H13990 and H13996 is a short section on the north side of the Boston Harbor main ship channel; the shared border is less than 400m long. Agreement between the two surveys here was very good, with a mean difference of 0.03m. Depth differences between surveys H13990 and H13996. file:///B:/OPR-A325-KR-24/Surveys/H13990/01_HDR/Reports/Descriptive_Report/SupportFiles/H13990_MB_50cm_MLLW-H13996_MB_50cm_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 North Cove and RV South Cove 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. H13990 Sound speed cast locations. file:///B:/OPR-A325-KR-24/Surveys/H13990/01_HDR/Reports/Descriptive_Report/SupportFiles/H13390-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, with 99.5+% of nodes populated with at least 5 soundings. Data density, 50cm resolution surface. file:///B:/OPR-A325-KR-24/Surveys/H13990/01_HDR/Reports/Descriptive_Report/SupportFiles/H13990_MB_50cm_MLLW_Final_1of2.GQv6.density.png Data density, 1m resolution surface. file:///B:/OPR-A325-KR-24/Surveys/H13990/01_HDR/Reports/Descriptive_Report/SupportFiles/H13990_MB_1m_MLLW_Final_2of2.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. H13990 multibeam backscatter mosaic. file:///B:/OPR-A325-KR-24/Surveys/H13990/01_HDR/Reports/Descriptive_Report/SupportFiles/H13390-Backscatter.jpg NOAA Profile Version 2024 H13990_MB_50cm_MLLW_Final_1of2 CARIS Raster Surface (CUBE) 0.5 -2.3 20.0 NOAA_0.5m Object Detection H13990_MB_1m_MLLW_Final_2of2 CARIS Raster Surface (CUBE) 1 18.0 22.8 NOAA_1m Object Detection H13990_MB_50cm_MLLW_1of2 CARIS Raster Surface (CUBE) 0.5 -1.8 22.9 NOAA_0.5m Source H13990_MB_1m_MLLW_2of2 CARIS Raster Surface (CUBE) 1 -1.8 22.8 NOAA_1m Source H13990_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 OPR-A325-KR-24_NAD83(2011)-NPL.csar North American Datum 1983 (2011) Projected UTM 19 Smart Base Single Base Putnam CTPN Milton MAMI Plymouth MAPL Salisbury MASA Sturbridge MASB Tewksbury MATB Wrentham MAWR Machias MEMA Newport, RI N001 U New Hampshire NHUN U of RI Coop URIL Westford WES2 Boston WAAS 1 ZBW1 Ocean Surveys Gloucester OSGL US5BOSBE 22000 3 2025-02-19 2025-02-19 US5BOSBF 22000 3 2025-02-19 2025-02-19 US5BOSCC 12000 4 2025-02-25 2025-02-25 US5B0SCD 12000 4 2025-02-25 2025-02-25 US5BOSCE 22000 4 2025-02-19 2025-02-19 US5BOSDC 12000 4 2025-02-25 2025-02-25 US5BOSDD 12000 4 2025-02-25 2025-02-25 US5MA1OE 22000 3 2025-02-26 2025-02-26 US5MA1OF 22000 5 2025-02-26 2025-02-26 Numerous potentially hazardous features were surveyed in H13990 and DTON reports were submitted for 20 features. These DTONS consisted of wrecks, shoal soundings, and obstructions associated with ruined piers, with approximately equal frequency of each. More than 3200 features were assigned in H13990. Many were inshore of NALL and not investigated, but over 1000 are addressed in the FFF. In some areas, full multibeam coverage was obtained over unassigned charted features. These features are also included in the FFF with appropriate attribution. Hundreds of uncharted features were found throughout the survey area. New wrecks, obstructions, and areas of submerged ruins were common, as were new or repositioned docks, dolphins, and pilings. See the FFF for details. The Boston Harbor area contains many charted channels, and the assigned survey limits specifically exclude these channels. Any channel coverage was obtained incidentally, such as along the edges of channels at the survey boundaries or in narrow waterways where it was impractical to obtain coverage without including the channels. An investigation of channel depths was not conducted; however, maintained channels in the Boston Harbor area were generally at or below their charted depths. Some channels, such as the John Fitzgerald Kennedy Channel and the Squantum Channel in Dorchester Bay, are charted as unmaintained and were surveyed to be shoaler than the charted depths. More than 300 ATONS were charted within the assigned survey limits, and the majority were observed to be present as charted. A group of private aids near Spectacle Island were not observed; some of them are listed as seasonal aids. A pair of hazard buoys, Nantasket Roads DRC Lighted Hazard Buoys C and D, were also not present but were already listed as missing in the U.S. Coast Guard Light List. No reports were made to the US Coast Guard for this survey area. No Maritime Boundary Points were assigned for this survey. No bottom samples were required for this survey. No overhead features were found to be incorrectly positioned and no overhead clearance reports were submitted for this survey. An exposed cable was visible in a charted cable area, on the north side of Georges Island leading to the fog signal on Gallop Island Light 7. There were also 5 visible pipeline segments reported in the Exposed Pipeline Report, 1 of which was not near a charted pipeline. These pipeline segments are included in the FFF. Platform features exist for this survey, but were not categorized as drilling structures, production platforms, or well heads. Platforms are addressed in the FFF. Seasonal ferry routes exist for this survey, but the routes are not on the chart. No abnormal seafloor or environmental conditions exist for this survey. The bridge at the Charles River Dam was undergoing construction at the time of the survey. Caution areas for this construction are present on the current ENCs. No new surveys or further investigations are recommended for this area. Larger scale ENCs would be appropriate for the northwest portion of this survey which includes the city of Boston. 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