OPR-B360-KR-23 Nantucket Sound, MA Offshore of Nantucket Island, Martha's Vineyard, and Cape Cod, MA Ocean Surveys H13827 2 Nantucket Harbor to Approaches to Hyannis Massachusetts United States 10000 2023 John R. Bean Navigable Area 2023-07-26 2023-10-20 2024-06-01 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. 41.571472 70.283386 41.281723 70.0894 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 coverage with H13827 emphasized. file:///B:/OPR-B360-KR-23/Surveys/H13827/01_HDR/Reports/Descriptive_Report/SupportFiles/H13827-Overview.jpg H13827 SSS coverage. file:///B:/OPR-B360-KR-23/Surveys/H13827/01_HDR/Reports/Descriptive_Report/SupportFiles/H13827-SSS.jpg MV Northstar Challenger 0.0 0.6 0.0 0.0 0.0 419.4 0.0 21.1 0.0 RV North Cove 0.0 23.2 0.0 0.0 0.0 172.2 0.0 0.0 0.0 RV South Cove 0.0 18.3 0.0 0.0 0.0 46.8 0.0 6.2 0.0 0.0 42.1 0.0 0.0 0.0 638.4 0.0 27.3 0.0 4.0 0 0 0 0 40.0 2023-10-20 2023-10-21 2023-10-24 2023-10-25 2023-10-26 2023-10-27 2023-10-28 2023-11-02 2023-11-07 2023-12-06 2023-12-07 2024-02-08 2024-02-09 2024-05-24 2024-05-25 2024-05-26 2024-06-01 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 MV Northstar Challenger configured for survey operations. file:///B:/OPR-B360-KR-23/Surveys/H13827/01_HDR/Reports/Descriptive_Report/SupportFiles/Vessel-CH.jpg RV North Cove configured for survey operations. file:///B:/OPR-B360-KR-23/Surveys/H13827/01_HDR/Reports/Descriptive_Report/SupportFiles/Vessel-NC.png RV South Cove configured for survey operations. file:///B:/OPR-B360-KR-23/Surveys/H13827/01_HDR/Reports/Descriptive_Report/SupportFiles/Vessel-SC.jpg MBES Teledyne RESON SeaBat T50-R SSS EdgeTech 4125 SSS EdgeTech 4200 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 Crossline mileage in H13827 totaled 4.0% of the mainscheme survey miles. Agreement between crosslines and mainscheme bathymetry was very good, with a mean difference of 0.01m in the 1m resolution surface. Crossline tracks overlaid on a coverage surface. file:///B:/OPR-B360-KR-23/Surveys/H13827/01_HDR/Reports/Descriptive_Report/SupportFiles/H13827-XL.jpg Depth differences between mainscheme and crossline data. file:///B:/OPR-B360-KR-23/Surveys/H13827/01_HDR/Reports/Descriptive_Report/SupportFiles/H13827_MB_1m_Main-H13827_MB_1m_XL_depth_delta.png ERS via VDATUM 13.06 MV Northstar Challenger 2 1 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, 1m resolution surface. file:///B:/OPR-B360-KR-23/Surveys/H13827/01_HDR/Reports/Descriptive_Report/SupportFiles/H13827_MB_1m_MLLW_Final.GQv6.tvu_qc.png Survey H13827 junctions with contemporary surveys along its eastern, western, and northern borders. Prior USGS surveys junction with the northern border and overlap with an area at the southern end of H13827. H13827 junction map with junction area depth differences. file:///B:/OPR-B360-KR-23/Surveys/H13827/01_HDR/Reports/Descriptive_Report/SupportFiles/H13827-Junction.jpg W00718 20000 2022 U.S. Geological Survey NW Part of the northern border of H13827 junctions with prior survey W00718. The shared border is approximately 1.5km long and has sand waves throughout the overlap area. The sand wave positions do not quite align between the two surveys, and they also appear to have a smaller amplitude in H13827 than W00718. Shifting sand waves account for some of the discrepancies between the two surveys, however, the current survey is also consistently deeper than W00718. The mean depth difference is 0.43m. Depth differences between H13827 and W00718. file:///B:/OPR-B360-KR-23/Surveys/H13827/01_HDR/Reports/Descriptive_Report/SupportFiles/H13827_MB_1m_MLLW-W00718_MB_2m_MLLW_depth_delta.png W00488 20000 2019 U.S. Geological Survey SE Survey W00488 crosses the southern end of H13827, with tracklines running perpendicular to the current survey. The junction area is approximately 4.4 SNM. Agreement between the two surveys is good, with a mean difference of 0.07m. Differences were greatest in an oval shoal area in the northern part of the junction and in striped sections across the junction area that may be from outer beam data. Depth differences between H13827 and W00488. file:///B:/OPR-B360-KR-23/Surveys/H13827/01_HDR/Reports/Descriptive_Report/SupportFiles/H13827_MB_1m_MLLW-W00488_IF_5m_MLLW_1of1_depth_delta.png H13826 10000 2023 OSI N This junction is discussed in the H13826 DR. H13830 10000 2023 OSI E Contemporary survey H13830 junctions with the eastern side of H13827 with a total border length of 13.3km. Agreement between the two surveys was very good, with an average difference of 0.02m. Depth differences between H13827 and H13830. file:///B:/OPR-B360-KR-23/Surveys/H13827/01_HDR/Reports/Descriptive_Report/SupportFiles/H13827_MB_1m_MLLW-H13830_MB_1m_MLLW_depth_delta.png H13831 10000 2023 OSI E This junction is addressed in the H13831 DR. H13832 10000 2023 OSI E Contemporary survey H13832 borders H13827 on the northern portion of its eastern border. The shared boundary is approximately 10km long, with patchy multibeam overlap due to the skunk-stripe coverage of both surveys. Agreement between the two surveys is very good, with an average difference of 0.01m. The greatest differences are found in the northern part of the junction, in the Bishop and Clerks rocky area. Depth differences between H13827 and H13832. file:///B:/OPR-B360-KR-23/Surveys/H13827/01_HDR/Reports/Descriptive_Report/SupportFiles/H13827_MB_1m_MLLW-H13832_MB_1m_MLLW_depth_delta.png H13833 10000 2023 OSI W Contemporary survey H13833 borders H13827 for a stretch near the center of its western border. The shared boundary is approximately 6.6km long, with patchy multibeam overlap due to the skunk-stripe coverage of both surveys. Agreement between the two surveys is very good, with an average difference of 0.04m. The greatest differences are found on sand waves. Depth differences between H13827 and H13833. file:///B:/OPR-B360-KR-23/Surveys/H13827/01_HDR/Reports/Descriptive_Report/SupportFiles/H13827_MB_1m_MLLW-H13833_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. MV Northstar Challenger acquired MVP casts at approximately 20 minute intervals. An AML-3 LGR was also onboard the MV Northstar Challenger as a backup for the MVP, and AML casts were acquired at intervals of approximately 2 hours. 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. H13827 sound speed cast locations. file:///B:/OPR-B360-KR-23/Surveys/H13827/01_HDR/Reports/Descriptive_Report/SupportFiles/H13827-SVP.jpg This survey was conducted to achieve Complete Coverage with 100% Side Scan Sonar and Concurrent Multibeam, as specified in HSSD 5.2.2.3, Option B. Complete 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. In data processing, the maximum water depth in H13827 was found to be 20.4m. Although 20m is the maximum depth for a 1m resolution surface, the area deeper than 20m was less than 0.01% of the survey area. The multibeam data density in a 1m resolution surface covering just water depths greater than 20m was analyzed and also found to meet the density coverage requirements, so an additional surface of 2m resolution was not included. Data density, 1m resolution surface. file:///B:/OPR-B360-KR-23/Surveys/H13827/01_HDR/Reports/Descriptive_Report/SupportFiles/H13827_MB_1m_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. H13827 multibeam backscatter mosaic. file:///B:/OPR-B360-KR-23/Surveys/H13827/01_HDR/Reports/Descriptive_Report/SupportFiles/H13827-Backscatter.jpg NOAA Profile Version 2023 H13827_MB_1m_MLLW_Final CARIS Raster Surface (CUBE) 1 0.82 20.43 NOAA_1m Complete MBES H13827_MB_1m_MLLW CARIS Raster Surface (CUBE) 1 0.82 20.43 NOAA_1m Complete MBES H13827_SSAB_1m_600kHz_1of1 SSS Mosaic 1 N/A 100% SSS H13827_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 N001_NEWPORT_RI N001 Ocean Surveys Bass River OSBR US4MA43M 80000 27 2024-04-17 2024-05-09 US5MA1BR 10000 2 2023-02-07 2023-11-27 US5MA1CQ 20000 2 2022-12-20 2022-12-20 US5MA1CR 20000 2 2023-02-07 2023-02-07 US5MA1FO 20000 3 2023-09-11 2024-05-14 US5MA1FP 20000 2 2023-06-23 2023-06-23 US5MA20M 40000 28 2024-02-23 2024-02-23 US5MA41M 40000 16 2022-06-27 2023-12-19 A DTON report was submitted for a wreck with a tall mast that was surveyed at a new position. Survey H13827 has 4 charted features assigned: 3 wrecks and 1 obstruction. The obstruction was disproved, and 1 of the wrecks was found near its charted position. The other 2 wrecks were both disproved within their assigned search areas, but a wreck was found nearby each of them outside the search areas. See the FFF for details. There were 4 uncharted wrecks surveyed, 2 of which were found near charted wrecks. Multiple new sand wave areas with potential navigational significance were delineated. See the FFF for details. The entrance channel to Nantucket Harbor is within the survey area, with different depths charted for the right and left quarters and the middle halves of the inner and outer channel. The portions of the channel surveyed with multibeam coverage were found to be almost entirely at or below their charted depths. Two small patches in the Outer Channel ROQ and MH are just shoal of the charted 4.9m depth, and the southern corner of the Inner Channel ROQ where it nears the shoreline is shoaler than the charted 2.8m depth. Sand waves were observed in the channel and are included in the FFF as an area feature. Most of the ATONS in H13827 are associated with Nantucket Harbor, and were found to be on station. At the time of survey, the harbor also contained an array of "winter stick" markers in the mooring field, which were not included in the FFF. Outside of Nantucket Harbor, 3 ATONS are charted in H13827. All were found to be on station. No Maritime Boundary Points were assigned for this survey. No bottom samples were required for this survey. No overhead features exist for this survey. There are 2 submarine cables charted in H13827 running approximately north-south across the sheet. No sign of the western cable was observed in survey data, but a small linear depression was found along the southern portion of the eastern cable. The depression is visible in SSS and MB data, and measures approximately 10cm in depth. No platforms exist for this survey. Nantucket Harbor, at the south end of H13827, serves ferries from New Bedford, Hyannis, Martha's Vineyard, and Harwich Port (www.nantucketferries.com). Ferries were observed by the field crews during the project. No ferry routes are shown on the charts for this survey. An area of sand waves was surveyed in the Nantucket Harbor entrance channel, primarily alongside the east breakwater. Most survey data collected was on a single day so sand wave movement was not obvious throughout the area, but changes were evident in the places where data from different survey days overlapped. These sand waves, along with other surveyed sand wave areas, are included in the FFF as a new features with potential navigational significance. 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