S-A928-NRTNL-23 Cape Cod Bay Cape Cod Bay NOAA NRT-New London H13792 1 Wellfleet Harbor Massachusetts United States 10000 2023 LTJG Mark Meadows Navigable Area 2023-04-12 2023-04-19 2023-05-24 Multibeam Echo Sounder Multibeam Echo Sounder Backscatter meters UTC Pacific 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 Field Units) CC0-1.0 https://creativecommons.org/publicdomain/zero/1.0/ https://creativecommons.org/publicdomain/zero/1.0/legalcode These data were produced by NOAA and are in the public domain within the United States. NOAA waives any potential copyright and related rights in these data worldwide through the Creative Commons Zero 1.0 Universal Public Domain Dedication (CC0). NOAA The survey area covers the approach to Wellfleet harbor, continues south of Jeremy Point, and terminates around the shipwreck of SS James Longstreet. 41.930758 70.080663 41.824375 70.023668 Survey limits were not fully acquired in the southern portion of the survey. NRT-NL prioritized the northern, more heavily trafficked, and shoaler working grounds. Wellfleet Harbor and Provincetown Harbor are both in need of a modern hydrographic surveys. The charted data in these areas are from 1933. In Wellfleet Harbor, the USCG and the harbormaster have both requested a survey due to vessels running aground and the new data updating the charts. Also, the data from this survey will help the USCG with the placement of aids to navigation. Survey data from this project is intended to supersede all prior survey data in the common area. The entire survey is adequate to supersede previous data. The Grid QC tool within QC Tools was used to analyze multibeam echosounder (MBES) data density. The MBES surfaces meet the HSSD data density requirement. Pydro derived histogram plot showing HSSD object detection compliance of H13792 MBES data within the 50cm CUBE surface. file:///M:/SA928NRTNL23/Surveys/H13792/01_HDR/Reports/Descriptive_Report/Components/DR_Images/H13792_MB_50cm_MLLW_Final.GQv6.density.png All 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 with some exceptions. As stated in section A.2, the southern portion of the survey grounds were not covered. Pydro Explorer's Flier Finder tool found 356 fliers. These were investigated and all but one are located on top of the shipwreck SS James Longstreet, with the lone other flier being on a steep slope. Pydro Explorer's Holiday Finder showed 31 holidays, which were investigated and all were found to be small, and mostly caused by deletion of noisy data. No navigationally significant features appear to be contained within them. Survey coverage of H13792 data. file:///M:/SA928NRTNL23/Surveys/H13792/01_HDR/Reports/Descriptive_Report/Components/DR_Images/Overview.png S3007 0.0 721.99 0.0 0.0 0.0 0.0 0.0 19.795 0.0 0.0 721.99 0.0 0.0 0.0 0.0 0.0 19.795 0.0 2.74 0 0 0 0 5.312 2023-04-19 2023-04-20 2023-04-21 2023-04-22 2023-05-10 2023-05-11 2023-05-12 2023-05-13 2023-05-14 2023-05-15 2023-05-16 2023-05-17 2023-05-18 2023-05-19 2023-05-21 2023-05-23 2023-05-24 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. S3007 10.38 0.6 MBES Kongsberg Maritime EM 2040C Positioning and Attitude System Applanix POS MV 320 v5 Conductivity, Temperature, and Depth Sensor YSI CastAway-CTD Sound Speed System AML Oceanographic Micro SV-Xchange A 4cm CUBE surface was created using only mainscheme lines and a second 4cm CUBE surface was created using only crosslines. These surfaces were then input into the Pydro Tool "Compare Grids". The comparison passed HSSD specifications. Pydro generated graph showing percentage of nodes that pass the allowable error fraction between mainscheme and crosslines. file:///M:/SA928NRTNL23/Surveys/H13792/01_HDR/Reports/Descriptive_Report/Components/DR_Images/MS_only_4m-XLs_4m_fracAllowErr_Freq.png Pydro generated graph showing deviations between mainscheme and crosslines. file:///M:/SA928NRTNL23/Surveys/H13792/01_HDR/Reports/Descriptive_Report/Components/DR_Images/MS_only_4m-XLs_4m_depth_delta.png Concur with clarification, the crossline comparison was done at 4 meters not at 4 centimeters as described in section. B.2.1 Crosslines. ERS via VDATUM 0.0 0.129 S3007 2 0 0 0.2 Total Propagated Uncertainty (TPU) values for H13792 were derived from a combination of fixed values for equipment and vessel characteristics, as well as field assigned values for sound speed uncertainties. The uncertainty for the VDatum model was provided to the field units. A visual inspection of the Uncertainty layer revealed the areas of higher uncertainty occur in the outer beams, and a visual inspection of the Density layer revealed the areas of lowest density are in the deepest areas of the survey. In addition to the usual a priori estimates of uncertainty, some real time and post processed uncertainty sources were also incorporated into the depth estimates of the survey. Real-time uncertainties from the Kongsberg MBES sonars were incorporated and applied during post processing. Uncertainties associated with vessel roll, pitch, gyro, navigation, and heave were applied during post-processing. All of the aforementioned uncertainties were applied in CARIS. As stated, H13792 is an ellipsoidally referenced survey (ERS) and the tidal component was accomplished with a separation model. Pydro generated graph showing Uncertainty Standards compliance of H13792 data. file:///M:/SA928NRTNL23/Surveys/H13792/01_HDR/Reports/Descriptive_Report/Components/DR_Images/H13792_MB_50cm_MLLW_Final.GQv6.tvu_qc.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. None Exist There were no other factors that affected corrections to soundings. At least once every 4 hours. SVP casts were taken at least once every four hours in the deepest water nearest to the survey area being worked on. The SVP casts were applied to the MBES lines in CARIS using the "nearest in distance within time of 4 hours" method. All equipment and survey methods were used as detailed in the DAPR. 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. NOAA Profile Version 2023 H13792_MB_50cm_MLLW CARIS Raster Surface (CUBE) 0.5 -1.021 12.931 NOAA_0.5m Complete MBES H13792_MB_50cm_MLLW_Final CARIS Raster Surface (CUBE) 0.5 -1.958 12.931 NOAA_0.5m Complete MBES 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 S-A928_VDatum_100m_NAD83-MLLW_geoid12b North American Datum 1983 Projected UTM 19 Smart Base RTX BAR HARBOR BARH PLYMOUTH MAPL TRURO MATU CHATHAM MACM FALMOUTH MAFA NANTUCKET MANT The Wide Area Augmentation System (WAAS) was used for real-time horizontal control during data acquisition. US5MA1IS 20000 1 2022-07-18 2022-07-18 US5MA1IR 20000 1 2022-07-18 2022-07-18 US5MA1KS 20000 1 2022-08-24 2022-08-24 US5MA1JS 20000 1 2022-08-24 2022-08-24 US5MAJR 20000 1 2022-08-24 2022-08-24 The shipwreck of SS James Longstreet is hazardous, however, it is correctly charted. Also, the shoal at Jeremy Point has shifted since last charted. No DTON Reports have been submitted for this survey. Shoal at Jeremy Point moved approximately 200m southeast. file:///M:/SA928NRTNL23/Surveys/H13792/01_HDR/Reports/Descriptive_Report/Components/DR_Images/Jeremy_Point_V2.png All charted features are discussed in the FFF. Charted soundings and H13792 soundings generally agree in value. No uncharted features exist for this survey. The approach to Wellfleet harbor has a dredged channel that is correctly maintained. The anchorage area within Wellfleet harbor has a depth range value of 3.1 meters, however, not all areas within the area are at that maintained depth. The harbormaster was provided a preliminary chartlet. All ATONs were found to be on station and serving their intended purpose. No Maritime Boundary Points were assigned for this survey. No bottom samples were required for this survey. No overhead features exist for this survey. No submarine features exist for this survey. No platforms exist for this survey. No ferry routes or terminals exist 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. LTJG Mark Meadows Chief of Party 2023-12-19 PST Michael Bloom Sheet Manager 2023-12-19