OPR-B360-KR-23 Nantucket Sound, MA Offshore of Nantucket Island, Martha's Vineyard, and Cape Cod, MA Ocean Surveys H13830 5 6 NM Southeast of Hyannis Massachusetts United States 10000 2023 John R. Bean Navigable Area 2023-07-26 2023-10-24 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. 41.466031 70.15938700000001 41.360587 69.948811 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 H13830 emphasized. file:///B:/OPR-B360-KR-23/Surveys/H13830/01_HDR/Reports/Descriptive_Report/SupportFiles/H13830-Overview.jpg H13830 SSS coverage. file:///B:/OPR-B360-KR-23/Surveys/H13830/01_HDR/Reports/Descriptive_Report/SupportFiles/H13830-SSS.jpg MV Northstar Challenger 0.0 0.4 0.0 0.0 0.0 356.0 0.0 18.1 0.0 RV North Cove 0.0 38.4 0.0 0.0 0.0 71.2 0.0 0.0 0.0 RV South Cove 0.0 52.3 0.0 0.0 0.0 68.5 0.0 5.6 0.0 0.0 91.1 0.0 0.0 0.0 495.7 0.0 23.7 0.0 4.7 0 0 0 0 30.3 2023-10-24 2023-10-26 2023-10-28 2023-11-01 2023-11-02 2023-11-03 2023-11-04 2023-11-05 2023-11-06 2024-04-15 2024-04-16 2024-05-07 2024-05-25 2024-05-31 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/H13830/01_HDR/Reports/Descriptive_Report/SupportFiles/Vessel-CH.jpg RV North Cove configured for survey operations. file:///B:/OPR-B360-KR-23/Surveys/H13830/01_HDR/Reports/Descriptive_Report/SupportFiles/Vessel-NC.png RV South Cove configured for survey operations. file:///B:/OPR-B360-KR-23/Surveys/H13830/01_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 H13830 totaled 4.7% of the mainscheme survey miles. Survey H13830 includes 4 submitted surfaces covering different time frames due to the movement of sand waves over the course of the survey, but a single mainscheme surface of all survey data was used for crossline comparison purposes. Despite the changes in bathymetry over time, agreement between crosslines and mainscheme bathymetry was very good, with a mean difference of 0.01 in the 1m resolution surface. Crossline tracks overlaid on a coverage surface. file:///B:/OPR-B360-KR-23/Surveys/H13830/01_HDR/Reports/Descriptive_Report/SupportFiles/H13830-XL.jpg Depth differences between mainscheme and crossline data. file:///B:/OPR-B360-KR-23/Surveys/H13830/01_HDR/Reports/Descriptive_Report/SupportFiles/H13830_MB_1m_Main-H13830_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. Four surfaces covering different date ranges were 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 passed the uncertainty check, with 99.5+% or 100% of nodes meeting the uncertainty standards in each surface. A single combined surface of all data was also finalized and analyzed, and as the results were similar to each of the other submitted surfaces, only the single surface analysis is shown here for simplicity. Uncertainty standards, 1m resolution surface. file:///B:/OPR-B360-KR-23/Surveys/H13830/01_HDR/Reports/Descriptive_Report/SupportFiles/H13830_MB_1m_MLLW_1of5_Final.GQv6.tvu_qc.png Survey H13830 junctions with contemporary surveys along its northern and western borders, and along a short section of its southern border. Prior surveys junction with portions of the eastern and southern borders. For H13830 and other surveys in this project with multiple submitted surfaces covering different date ranges, a single surface that includes all days of that survey was used for the junction comparisons. H13830 junction map with junction area depth differences. file:///B:/OPR-B360-KR-23/Surveys/H13830/01_HDR/Reports/Descriptive_Report/SupportFiles/H13830-Junction.jpg H11079 20000 2004 Thomas Jefferson SE The shared border between surveys H13830 and H11079 is approximately 11.3km in total length, with the eastern border of H13830 overlapping 3 sides of the western end of H11079 in an approximate C-shape around it. The mean depth difference between the surveys is 0.09m. The junction area shows evidence of sand waves that have moved over time, which accounts for much of the variation between the two surveys. Depth differences between surveys H13830 and H11079. file:///B:/OPR-B360-KR-23/Surveys/H13830/01_HDR/Reports/Descriptive_Report/SupportFiles/H13830_MB_1m_MLLW-H11079_MB_2m_MLLW_1of1_depth_delta.png W00488 20000 2019 U.S. Geological Survey SE Survey W00488 junctions with the southern end of H13830, with a shared border approximately 5km long. The eastern end of the junction includes an area of sand waves, and the center and western end are relatively flat. The mean depth difference between the two surveys is 0.15m. Differences are greatest in the eastern sand wave area, and along the edges of the tracklines of W00488. Depth differences between surveys H13830 and W00488. file:///B:/OPR-B360-KR-23/Surveys/H13830/01_HDR/Reports/Descriptive_Report/SupportFiles/H13830_MB_1m_MLLW-W00488_IF_5m_MLLW_1of1_depth_delta.png H13827 10000 2023 OSI W This junction is addressed in the H13827 DR. H13831 10000 2023 OSI N This junction is addressed in the H13831 DR. 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. H13830 sound speed cast locations. file:///B:/OPR-B360-KR-23/Surveys/H13830/01_HDR/Reports/Descriptive_Report/SupportFiles/H13830-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 in each of the submitted surfaces met the density coverage requirements. All surfaces passed the check with 99% or more of the grid nodes populated with at least 5 soundings. For simplicity, the results shown below are only for a single surface including all the multibeam data, as the results were similar to the set of surfaces covering different date ranges. The maximum water depth in H13830 was 24.1m. Although 20m is the maximum depth for a 1m resolution surface, the area deeper than 20m was only 1.1% 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 additional surfaces of 2m resolution were not included. Data density, 1m resolution surface. file:///B:/OPR-B360-KR-23/Surveys/H13830/01_HDR/Reports/Descriptive_Report/SupportFiles/H13830_MB_1m_MLLW_1of5_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. H13830 multibeam backscatter mosaic. file:///B:/OPR-B360-KR-23/Surveys/H13830/01_HDR/Reports/Descriptive_Report/SupportFiles/H13830-Backscatter.jpg NOAA Profile Version 2023 H13830_MB_1m_MLLW_1of5_Final CARIS Raster Surface (CUBE) 1 1.6 24.07 NOAA_1m Complete MBES H13830_MB_1m_MLLW_2of5_Final CARIS Raster Surface (CUBE) 1 3.26 23.53 NOAA_1m Complete MBES H13830_MB_1m_MLLW_3of5_Final CARIS Raster Surface (CUBE) 1 2.56 22.22 NOAA_1m Complete MBES H13830_MB_1m_MLLW_4of5_Final CARIS Raster Surface (CUBE) 1 7.57 24.07 NOAA_1m Complete MBES H13830_MB_1m_MLLW_5of5_Final CARIS Raster Surface (CUBE) 1 1.6 23.23 NOAA_1m Complete MBES H13830_MB_1m_MLLW_1of5 CARIS Raster Surface (CUBE) 1 1.6 24.07 NOAA_1m Complete MBES H13830_MB_1m_MLLW_2of5 CARIS Raster Surface (CUBE) 1 3.26 23.53 NOAA_1m Complete MBES H13830_MB_1m_MLLW_3of5 CARIS Raster Surface (CUBE) 1 2.56 22.22 NOAA_1m Complete MBES H13830_MB_1m_MLLW_4of5 CARIS Raster Surface (CUBE) 1 7.57 24.07 NOAA_1m Complete MBES H13830_MB_1m_MLLW_5of5 CARIS Raster Surface (CUBE) 1 1.6 23.23 NOAA_1m Complete MBES H13830_SSSAB_1m_600kHz_1of1 SSS Mosaic 1 N/A 100% SSS H13830_MBAB_2m_400kHz_1of1 MB Backscatter Mosaic 2 N/A Processed Backscatter Survey H13830 was conducted over more than 7 months, with data collection days spread out due to weather conditions and survey priorities of the project. Over this time frame, significant changes were observed in the bathymetry as sand waves shifted and migrated. These changes were less apparent early in the survey as mainscheme data was collected across the area with minimal overlap between days, but investigations and fills collected later in the survey showed larger differences from previous data. Per guidance from the NOAA OCS Project Manager, the submitted surfaces have been divided into groups of days to best reflect the bathymetry as observed. A surface inclusive of all data is also provided, showing artifacts of the changed bathymetry. Summary of dates included in each submitted MB grid. file:///B:/OPR-B360-KR-23/Surveys/H13830/01_HDR/Reports/Descriptive_Report/SupportFiles/H13830-surface-date-ranges.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-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 RIVERHEAD NYRH Ocean Surveys Bass River OSBR US5MA1CQ 20000 2 2022-12-20 2022-12-20 US5MA1CR 20000 2 2023-02-07 2023-02-07 US5MA41M 40000 16 2022-06-27 2023-12-19 Point Rip, a shoal area along the southern border of the survey, was found to extend farther north than charted. A DTON report was submitted with surveyed soundings showing the change in the shoal extent. The only feature charted in H13830 was an area of sand waves on the southern border of the survey area. Sand waves were observed in the data across nearly the entire sheet, so the charted feature did not adequately describe the conditions surveyed. There were 2 uncharted wrecks surveyed in H13830. Multiple new sand wave area features were delineated, as well as a water turbulence area. See the FFF for details. No maintained channels exist within the survey limits. There were 4 buoys charted in H13830; 2 marking Great Round Shoal Channel at different points and 2 for Point Rip and Point Rip Shoal. All 4 buoys were observed 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. A charted cable crosses H13830 on its western side. No indication of the cable was visible in the survey data. No platforms exist for this survey. The ferry route between Harwich, MA and Nantucket Island crosses through H13830. Ferries were observed by the field crews during the project. No ferry routes are shown on the charts for this survey. Most of the seafloor in H13830 is covered by sand waves, which were observed to have shifted over the course of the survey. The submitted surfaces for H13830 include a set of 4 partial-coverage surfaces from different times in the data collection period, which were separated based on the mismatch of sand waves in overlapping data. Early survey days covered the majority of the area and are all included in the first of these partial coverage surfaces. The other 3 surfaces are made from data collected 5 or more months later and include the 2 eastern spurs, a southern area where the water depths change rapidly approaching Point Rip Shoal, and investigations and fills across the entire survey area. The figure shows a cross section view of sand waves on two survey lines, data collected on DN 2023-305 (purple) and 2024-153 (tan), at 5x vertical exaggeration. Water depths and horizontal distance are labeled in meters. Water turbulence was also observed by the field crew, and an area feature categorized as tide rips has been included in the FFF. Cross sectional view of sand waves on different survey days with 5x vertical exaggeration. file:///B:/OPR-B360-KR-23/Surveys/H13830/01_HDR/Reports/Descriptive_Report/SupportFiles/H13830-shifted-sand-waves.png 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