OPR-B360-KR-23 Nantucket Sound, MA Offshore of Nantucket Island, Martha's Vineyard, and Cape Cod, MA Ocean Surveys H13826 1 Approaches to Hyannis Massachusetts United States 10000 2023 John R. Bean Navigable Area 2023-07-26 2023-10-30 2024-06-04 Multibeam Echo Sounder Multibeam Echo Sounder Backscatter Side Scan Sonar 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 Nantucket Sound, MA. The general locations of the survey limits are presented in Table 1. 41.634449 70.34085499999999 41.556168 70.238866 Survey limits were acquired in accordance with the requirements in the Project Instructions and the HSSD. This project is located in Nantucket Sound, MA, a body of water between Cape Cod and the islands of Nantucket and Martha's Vineyard, MA. Surveying efforts will provide updated charting products and improve the hydrographic health of the region. The survey area has not been surveyed since the 1990s. Conducting a modern bathymetric survey in this region will identify hazards and changes to the seafloor and provide modern bathymetric data to update National Ocean Service (NOS) nautical charting products and support the Seabed 2030 global mapping initiative. The entire survey is adequate to supersede previous data. All waters in Sheet 1 Object Detection Coverage (Refer to HSSD Section 5.2.2.2) All waters in Sheets 2-8 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-B360-KR-23 MBES coverage with H13826 emphasized. file:///B:/OPR-B360-KR-23/Surveys/H13826/01_HDR/Reports/Descriptive_Report/SupportFiles/H13826-Overview.jpg H13826 SSS coverage. file:///B:/OPR-B360-KR-23/Surveys/H13826/01_HDR/Reports/Descriptive_Report/SupportFiles/H13826-SSS.jpg RV North Cove 0.0 45.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 RV South Cove 0.0 63.2 0.0 0.0 0.0 467.8 0.0 30.5 0.0 0.0 108.2 0.0 0.0 0.0 467.8 0.0 30.5 0.0 5.3 0 0 0 0 10.1 2023-10-30 2023-10-31 2023-11-02 2023-11-03 2023-11-09 2023-12-05 2023-12-06 2023-12-07 2023-12-08 2023-12-09 2024-01-24 2024-01-26 2024-01-27 2024-01-28 2024-01-31 2024-05-30 2024-06-02 2024-06-03 2024-06-04 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-B360-KR-23/Surveys/H13826/01_HDR/Reports/Descriptive_Report/SupportFiles/Vessel-NC.png RV South Cove configured for survey operations. file:///B:/OPR-B360-KR-23/Surveys/H13826/01_HDR/Reports/Descriptive_Report/SupportFiles/Vessel-SC.jpg MBES Teledyne RESON SeaBat T50-R SSS EdgeTech 4125 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 Crossline mileage in H13826 totaled 5.3% 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-B360-KR-23/Surveys/H13826/01_HDR/Reports/Descriptive_Report/SupportFiles/H13826-XL.jpg Depth differences between mainscheme and crossline data. file:///B:/OPR-B360-KR-23/Surveys/H13826/01_HDR/Reports/Descriptive_Report/SupportFiles/H13826_MB_50cm_Main-H13826_MB_50cm_XL_depth_delta.png ERS via VDATUM 13.06 RV North Cove 2 1 RV South Cove 2 1 The HydrOffice "QC Tools" application was used to calculate TVU QC, determined by a ratio of uncertainty to the allowable error per NOAA and IHO specifications. A surface 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 surface passed the uncertainty check, with 100% of nodes meeting the uncertainty standards. Uncertainty standards, 50cm resolution object detection coverage. file:///B:/OPR-B360-KR-23/Surveys/H13826/01_HDR/Reports/Descriptive_Report/SupportFiles/H13826_MB_50cm_MLLW_Final.GQv6.tvu_qc.png Survey H13826 junctions with contemporary surveys along its eastern, southern, and western borders. A prior USGS survey overlaps the southwest corner of H13826. H13826 junction map with junction area depth differences. file:///B:/OPR-B360-KR-23/Surveys/H13826/01_HDR/Reports/Descriptive_Report/SupportFiles/H13826-Junction.jpg W00718 20000 2022 U.S. Geological Survey NW The southwest corner of H13826 overlaps a prior USGS survey, with a junction area of approximately 1.0 sq km. The area contains sand waves that do not appear to have shifted significantly in the time between surveys. The depths surveyed in H13826 are consistently deeper than depths reported in W00718, with an average difference of 0.41m. Depth differences between H13826 and W00718. file:///B:/OPR-B360-KR-23/Surveys/H13826/01_HDR/Reports/Descriptive_Report/SupportFiles/H13826_MB_50cm_MLLW-W00718_MB_2m_MLLW_depth_delta.png H13827 10000 2023 OSI S The southern edge of H13826 junctions with the northern edge of H13827, with a junction area that is approximately 3.2km long. The tracklines between the two sheets are perpendicular to one another and H13826 has tighter line spacing in this area. The two surveys had good agreement in the junction area, with a mean difference of 0.01m. Depth differences between H13826 and H13827. file:///B:/OPR-B360-KR-23/Surveys/H13826/01_HDR/Reports/Descriptive_Report/SupportFiles/H13826_MB_50cm_MLLW-H13827_MB_1m_MLLW_depth_delta.png H13829 10000 2023 OSI SE The junction between H13826 and H13829 follows the western edge of H13826 with a total shared border length of approximately 11.0km. Discrepancies between the two surveys were minimal, with a mean depth difference of 0.00m. Depth differences between H13826 and H13829. file:///B:/OPR-B360-KR-23/Surveys/H13826/01_HDR/Reports/Descriptive_Report/SupportFiles/H13826_MB_50cm_MLLW-H13829_MB_50cm_MLLW_depth_delta.png H13832 10000 2023 OSI W The northwest corner of H13832 junctions with H13826 on both the northern and western sides of H13832, with a total junction length of 5.0km. Both surveys have tight line spacing in this area so the junction area is dense with MBES soundings. Differences were observed in rocky areas on the northern side of H13832, but overall depth discrepancies were minimal with a mean difference of 0.00m. Depth differences between H13826 and H13832. file:///B:/OPR-B360-KR-23/Surveys/H13826/01_HDR/Reports/Descriptive_Report/SupportFiles/H13826_MB_50cm_MLLW-H13832_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 North Cove and RV South Cove acquired AML3 casts at approximately 90 minute intervals. 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, and RV South Cove in North Atlantic Ocean, Nantucket Sound from 2023-10-18 to 2024-06-04" in NetCDF format to the National Centers for Environmental Information (NCEI) on August 7, 2024. H13826 sound speed cast locations. file:///B:/OPR-B360-KR-23/Surveys/H13826/01_HDR/Reports/Descriptive_Report/SupportFiles/H13826-SVP.jpg This survey was conducted to achieve Object Detection Coverage with 200% Side Scan Sonar and Concurrent Multibeam, as specified in HSSD 5.2.2.2, Option B. Object Detection Multibeam Coverage was used for feature developments and disprovals. The survey methods used to meet coverage requirements did not deviate from those described in the DAPR. The HydrOffice "QC Tools" application was used to verify that the multibeam data met the density coverage requirements, with 99.5+% of the grid nodes populated with at least 5 soundings. Data density, 50cm resolution object detection coverage. file:///B:/OPR-B360-KR-23/Surveys/H13826/01_HDR/Reports/Descriptive_Report/SupportFiles/H13826_MB_50cm_MLLW_Final.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. H13826 multibeam backscatter mosaic. file:///B:/OPR-B360-KR-23/Surveys/H13826/01_HDR/Reports/Descriptive_Report/SupportFiles/H13826-Backscatter.jpg NOAA Profile Version 2023 H13826_MB_50cm_MLLW_Final CARIS Raster Surface (CUBE) 0.5 0.33 11.59 NOAA_0.5m Object Detection H13826_MB_50cm_MLLW CARIS Raster Surface (CUBE) 0.5 0.54 11.59 NOAA_0.5m Object Detection H13826_SSSAB_1m_600kHz_1of2 SSS Mosaic 1 N/A 100% SSS H13826_SSSAB_1m_600kHz_2of2 SSS Mosaic 1 N/A 200% SSS H13826_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-B360-KR-23_NAD83_VDatum_MLLW.csar OPR-B360-KR-23_NAD83_VDatum_MHW.csar North American Datum 1983 (2011) Projected UTM 19 Smart Base MACM CHATHAM MACM DARTMOUTH MADA FALMOUTH MAFA MANT NANTUCKET MANT PLYMOUTH MAPL TRURO MATU Ocean Surveys Bass River OSBR The survey area for H13826 is entirely covered by the 4 charts of 1:20000 scale listed in Table 14. The smaller scale chart US4MA43M is included in the discussion due to discrepancies between it and US5MA1FO regarding the position of charted named rocks. US5MA1FO 20000 3 2023-09-11 2023-12-19 US5MA1FP 20000 2 2023-06-23 2023-06-23 US5MA1GO 20000 2 2023-07-31 2023-12-19 US5MA1GP 20000 2 2023-06-23 2023-09-11 US4MA43M 80000 27 2024-04-17 2024-05-09 Survey H13826 includes a number of large rocks, some of which were shoal enough compared to charted depths to be potentially hazardous. DTON reports were submitted for multiple individual rocks, which are included in the FFF. Charted features that were surveyed in H13826 included 3 obstructions, 3 wrecks, and 45 rocks. All 3 wrecks were found with new positions, and 1 obstruction was found to be a linear feature better represented by a line than the existing charted point feature. The other 2 obstructions were found to be rocks/rocky areas and are not recommended for continued representation on chart. Most of the investigated rocks were also found to be adequately represented in the bathymetry grid and recommended for deletion from the chart. The charted named rocks surveyed in H13826 were identified and their surveyed positions included in the FFF as new features. There were 10 named rocks found, 9 of which were assigned in this survey and 1 assigned in adjacent survey H13829. Most named rocks needed only a small position update, but Channel Rock, Gallatin Rock, and Southwest Rock were misidentified on the current largest scale chart for this area (US5MA1FO). The correct rocks were identified using the Coast Pilot descriptions, the current smaller scale chart for this area (US4MA43M), historical charts, and the ATON positions. Channel Rock and Gallatin Rock are correctly identified on US4MA43M and marked by charted buoys at the correct positions. Southwest Rock is misidentified on both ENCs, but it is also marked by a charted buoy at the correct position. Southwest Rock was the site of a former beacon, which is now in ruins. The elevation measured in the FFF reflects the height of the beacon remnant atop Southwest Rock. Uncharted features surveyed in H13826 included 3 new wrecks, 2 new obstructions, and 1 land area for an exposed rock that supports a charted beacon. Potentially hazardous or noteworthy rocks are also included as new features. See the FFF for details. A channel labeled "13-Foot Nantucket Sound" is charted at the northeastern end of the survey, providing access to Lewis Bay and Hyannis. Charted dredge area depths are 3.0m, 3.2m, and 3.3m for the left, right, and middle sections, respectively. The portion of the channel within the sheet limits was surveyed and found to be primarily at or below the charted depths. Only 1 location had depths shoaler than 3m: a thin strip on either side of the channel where it is marked by Lewis Bay Approach Channel Lighted Buoys 9 and 10. Most ATONS in H13826 were buoys marking hazardous rocks or buoys indicating the Lewis Bay Approach Channel. All charted ATONS were found at or near their charted positions and appeared to be operating as intended. No Maritime Boundary Points were assigned for this survey. No bottom samples were required for this survey. No overhead features exist for this survey. A charted cable runs approximately north-south through the center of H13826. No evidence of the cable was observed in survey data. No platforms exist for this survey. Ferry routes between Hyannis, MA and Nantucket Island or Martha's Vineyard cross through H13826. Ferries were observed by the field crews during the project. No ferry routes are shown on the charts for this survey. 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 2024-10-30 David T. Somers Data Processing Manager 2024-10-30 Kelley J. Bostrom Sheet Manager 2024-10-30