OPR-E350-KR-20Central Chesapeake Bay, Virginia and MarylandAreas of Mobjack Bay, VA and Choptank River, MDLeidosH133412South Mobjack BayVirginiaUnited States200002020Erin MarkhamBasic Hydrographic Survey2020-08-192020-09-062020-11-13Multibeam Echo SounderMultibeam Echo Sounder BackscatterSide Scan SonarmetersUTCAtlantic Hydrographic BranchContract: 1305M220DNCNJ0056/TO-0001. Contractor: Leidos, 221 Third Street, Newport, RI 02840 USA. Subcontractors: Divemasters, Inc., 15 Pumpshire Road, Toms River, NJ 08753; OARS, 8705 Shoal Creek Blvd, Suite 109, Austin, TX 78757. Leidos Doc. 21-TR-005. All times were recorded in UTC. Final data are corrected to North American Datum of 1983 (NAD83) 2011 realization 2010 (NAD83(2011)2010.0), UTM Zone 18N.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 18N, MLLW. All references to other horizontal or vertical datums in this report are applicable to the processed hydrographic data provided by the field unit.ContractorThe area surveyed was a section of the Chesapeake Bay in South Mobjack Bay (Figure 1).37.33345476.4560737.2631976.28559H13341 Survey BoundsSupportFiles\H13341_Figure_01.jpgSurvey limits were acquired in accordance with the requirements in the Project Instructions and the Hydrographic Surveys Specifications and Deliverables (HSSD), May 2020.The central Chesapeake Bay is a critical shipping corridor for commerce transiting to and from the Port of Baltimore, as well the region supports an important commercial fishery, which includes menhaden, crabs and oysters. The purpose of this project is to provide contemporary surveys to update National Ocean Service nautical charts and products to support navigation safety and monitor the health of the environment. Survey vintage predates the 1950s for the majority of the project area despite vessels transiting within close proximity to the seafloor. This covers approximately 203 square nautical miles that will close a critical gap in existing modern hydrographic data for the stretch between the entrance to Chesapeake Bay up through Baltimore, MD. This project will provide critical data for the updating of National Ocean Service (NOS) nautical charting products to increase maritime safety in the region. 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.Leidos warrants only that the survey data acquired by Leidos and delivered to NOAA under Contract 1305M220DNCNJ0056 reflects the state of the sea floor in existence on the day and at the time the survey was conducted. H13341 was surveyed in accordance with the following documents: 1. 1305M220DNCNJ0056/1305M220FNCNJ0278P21001 dated 19 August 2020 2. Hydrographic Surveys Specifications and Deliverables (HSSD), May 2020 3. OPR-E350-KR-20_PRF.000, received 02 September 2020 4. OPR-E350-KR-20_CSF.000, received 12 August 2020 5. OPR-E350-KR-20 Virtual Meeting with NOAA Responses.pdf, dated 23 March 2021H13341Complete Coverage (Refer to HSSD Section 5.2.2.2)8 meters water depth and shoalerSidescan may be acquired at an altitude of 6-20% of the range scaleLeidos chose to achieve the coverage requirement using Complete Coverage, Option B (100% side scan sonar coverage with concurrent multibeam). Survey coverage achieved was in accordance with the requirements in the Project Instructions and the HSSD (Figure 2 through Figure 4). Final Bathymetry Coverage for H13341SupportFiles\H13341_Figure_02.jpgFinal Side Scan Coverage for H13341 (First 100% coverage)SupportFiles\H13341_Figure_03.jpgFinal Side Scan Coverage for H13341 (Second 100% coverage)SupportFiles\H13341_Figure_04.jpgR/V Oyster Bay II00000541.64025.52000000541.64025.5204.71700012.62020-09-062020-09-072020-09-082020-09-132020-09-142020-09-152020-09-162020-09-172020-09-182020-09-212020-09-222020-09-232020-09-292020-10-032020-10-082020-10-212020-10-232020-10-242020-10-262020-10-272020-11-032020-11-042020-11-062020-11-122020-11-13Leidos used their ISS-2000 software on a Windows platform to acquire these survey data. Survey planning and data analysis were conducted using the Leidos SABER software on Red Hat Enterprise 7 Linux platforms. Side scan sonar (SSS) data were collected on a Windows platform using Klein’s SonarPro software. Subsequent processing and review of the SSS data, including the generation of coverage mosaics, were accomplished using SABER. A detailed description of the systems and vessel used to acquire and process these data is included in the Data Acquisition and Processing Report (DAPR) for OPR-E350-KR-20, delivered concurrently with this Descriptive Report (DR). There were no variations from the equipment configuration described in the DAPR.R/V Oyster Bay II303R/V Oyster Bay IISupportFiles\H13341_Figure_05.jpgThe R/V Oyster Bay II (Figure 5) was used to collected MBES (RESON SeaBat 7125 SV1), SSS (Klein 4900), and sound speed data during twelve hours per day survey operations. A detailed description of the vessel used is included in the DAPR.Teledyne RESONSeaBat 7125 SVMBESKlein Marine SystemsSystem 4900SSSApplanixPOS MV 320 v5Positioning and Attitude SystemAML OceanographicBaseX2Sound Speed SystemA detailed description of the equipment installed is included in the DAPR.Multibeam echo sounder/side scan sonar crosslines acquired for this survey totaled 4.71% of mainscheme acquisition. Refer to Separates II for details about how the crossing analyses were performed and a complete discussion of each analysis and tabular results. Figure 6 summarizes the crossline comparison results.Summary of Crossing AnalysisSupportFiles\H13341_Figure_06.jpgERS via VDATUM0.0900.20R/V Oyster Bay II1.01.01.01.0For specific details on the use and application of the SABER Total Propagated Uncertainty (TPU) model, refer to the DAPR. Once the TPU model was applied to the GSF bathymetry data, each beam was attributed with the horizontal uncertainty and the vertical uncertainty at the 95% confidence level. The vertical and horizontal uncertainty values, estimated by the TPU model for individual multibeam soundings, varied little across the dataset, tending to be most affected by beam angle. Individual soundings that had vertical and horizontal uncertainty values above IHO S-44 5th Edition, Order 1a were flagged as invalid during the uncertainty attribution. As discussed in the DAPR, SABER generates two vertical uncertainty surfaces; the Hypothesis Standard Deviation (Hyp. StdDev) and the Hypothesis Average Total Propagated Uncertainty (Hyp. AvgTPU). A third vertical uncertainty surface is generated from the larger value of these two uncertainties at each node and is referred to as the Hypothesis Final Uncertainty (Hyp. Final Uncertainty). The final H13341 1-meter PFM CUBE surface contained final vertical uncertainties that ranged from 0.210 meters to 0.469 meters. The IHO Order 1a maximum allowable vertical uncertainty was calculated to range between 0.500 to 0.516 meters, based on the minimum CUBE depth (0.705 meters) and maximum CUBE depth (9.668 meters). Results from the SABER Check PFM Uncertainty function identified that there were 0 nodes in the final H13341 1-meter PFM CUBE surface with final vertical uncertainties that exceeded IHO Order 1a allowable vertical uncertainty. The SABER Frequency Distribution Tool was also used to review the Hyp. Final Uncertainty surface within the final H13341 1-meter PFM grid. Results showed that 100.00% of all nodes had final uncertainties less than or equal to 0.469 meters.Per the Project Instructions, analysis of the H13341 junction with an adjacent survey was performed between H13341 and the survey listed in Table 9. Figure 7 shows the general locality of H13341 as it relates to the sheet to which junctions were performed. Analysis of the junctions with sheet H13303 were not conducted as data acquisition and processing for that sheet remain on-going. Refer to Separates II for details about how junction analyses were performed and a complete discussion of each analysis and tabular results.General Locality of H13341 with Junctioning SurveysSupportFiles\H13341_Figure_07.jpgH13301100002020Leidos, Inc.SEH13341 junctions with H13301 to the southeast; 100% of the comparisons agreed within ±0.128 meters, well below the calculated maximum allowable TVU of 0.504 meters.Sonar system quality control checks were conducted as detailed in the DAPR; quality control checks conducted during H13341 are reported in Separates I.None ExistThere were no conditions or deficiencies that affected equipment operational effectiveness.None ExistThere were no other factors that affected corrections to soundings.On the R/V Oyster Bay II, the BaseX2 was the primary system used to collect sound speed profile (SSP) data, refer to the DAPR for additional details. SSP data were obtained at intervals frequent enough to meet depth accuracy requirements. Section 5.2.3.3 of the HSSD requires that if the sound speed measured at the sonar head differs by more than two meters/second from the commensurate profile data, then another cast shall be acquired. All sound speed profiles applied for online bathymetry data collection were acquired within 500 meters of the bounds of the survey area as specified in Section 5.2.3.3 of the HSSD. Confidence checks of the sound speed profile casts were conducted by comparing at least two consecutive casts taken with different SSP sensors. Results for the sound speed confidence checks were conducted during H13341 can be found in Separates II within the “Comparison Cast Log” section. All individual SSP files are delivered with the H13341 data and are broken out into sub-folders, which correspond to the purpose of each cast. Also, all individual SSP files for H13341 have been concatenated into four separate files based on the purpose of the cast, provided in CARIS format files (.svp), and delivered under (H13341/Processed/SVP/CARIS_SSP) on the delivery drive. In accordance with HSSD Section 8.3.6, SSP files were also converted to NCEI format, as detailed in the DAPR, and provided as a separate delivery to NCEI. Refer to the DAPR and Separates II for additional details.All equipment and survey methods are detailed in the DAPR.Multibeam Coverage Analysis Leidos chose to achieve the complete coverage requirement using 100% side scan sonar coverage with concurrent multibeam bathymetry. To achieve this coverage, the SSS was set to 25-meter or 50-meter range scale, main scheme survey lines were collected at 40-meter or 80-meter, respectfully, to ensure 100% SSS coverage. The SABER Gapchecker program was used to flag MBES data gaps within the CUBE surface. Additionally, the entire surface was visually scanned for holidays at various points during the data processing effort. Additional survey lines were run to fill any holidays that were detected. Bathymetric data and side scan sonar imagery were reviewed and bathymetric splits were acquired if deemed necessary per Hydrographer’s discretion, as noted in Section 5.2.2.1 of the HSSD. A final review conducted on the CUBE Depth surface of the H13341 1-meter PFM grid showed that there were no holidays as defined for complete coverage surveys, HSSD Section 5.2.2.3. Any three by three node gaps were along the outer swath data beyond the side scan nadir coverage. The final H13341 CUBE PFM grids were examined for the number of soundings contributing to the chosen CUBE hypotheses for each node by running SABER’s Frequency Distribution Tool on the Hypothesis Number of Soundings (Hyp. # Soundings) surface. The Hyp. # Soundings surface reports the number of soundings that were used to compute the chosen hypothesis. Analysis was conducted on the Hyp. # Soundings surfaces from each of the PFM grids to ensure that the requirements for complete coverage surveys, as specified in HSSD Section 5.2.2.3 were met. Within the final 1-meter PFM grid 99.54% of all nodes contained five or more soundings. All data reduction procedures conform to those detailed in the DAPR.All sounding systems were calibrated as detailed in the DAPR. Multibeam files associated with calibration are provided within the H13341/Processed/Sonar_Data/H13341_MB/Calibration_Files/ directory.Side Scan Sonar (SSS) Coverage Analysis: For all details regarding SSS data processing, see the DAPR. Leidos chose to adhere to the coverage requirements in the Project Instructions using Complete Coverage, Option B (100% side scan sonar coverage with concurrent multibeam). As referenced in Section A.4, the Project Instructions provided a waiver to HSSD Section 6.1.2.3 for towed side scan towfish height. In waters less than 8 meters the towfish height above the bottom could be 6% of the range scale. Mosaics were analyzed for coverage at both 8% and 6% of range based on water depths greater or less than 8 meters. Leidos generated two separate coverage mosaics at 1-meter cell size resolution as specified in Section 8.2.1 of the HSSD. The first 100% and second 100% coverage mosaics were independently reviewed using tools in SABER to verify data quality and swath coverage. The SABER Gapchecker routine was used to flag data gaps within each of the 100% SSS coverage mosaics. Additionally, the entirety of each SSS surface was visually scanned for holidays at various points during the data processing effort. Additional survey lines were run to fill any holidays that were detected. Both coverage mosaics are determined to be complete and sufficient to meet the requirements contained within the Project Instructions and HSSD . Each 100 percent coverage mosaic is delivered as a single georeferenced raster file (datum of NAD83) in floating point GeoTIFF format, as specified in Sections 8.2.1 and 8.3.3 in the HSSD. Multibeam Echo Sounder Seafloor Backscatter: Leidos collected MBES backscatter data with all GSF data acquired, in accordance with HSSD Section 6.2. The MBES settings used were checked to ensure acceptable quality standards were met and to mitigate acoustic saturation of the backscatter data. The MBES backscatter data acquired were written to the GSF in real-time by ISS-2000 and are delivered in the final GSF files for this sheet. Evaluation of backscatter data and processing were not required for OPR-E350-KR-20 and therefore no additional processing was performed by Leidos and no additional products were produced. LeidosSABER5.4.0.35.0LeidosSABER5.4.0.35.0NOAA Profile Version 2021The primary data processing software used for both bathymetry and imagery was SABER. H13341_MB_1m_MLLW_FinalBAG10.7059.668N/AComplete coverage, Option B (100% side scan sonar coverage with concurrent multibeam)H13341_SSSAB_1m_900kHz_1of2SSS Mosaic (.tif)100N/AFirst 100% SSSH13341_SSSAB_1m_900kHz_2of2SSS Mosaic (.tif)100N/ASecond 100% SSS (Disproval) Complete Coverage Section 5.2.2.3 of the HSSD requires 1-meter node resolution for depths ranging from 0 meters to 20 meters. Leidos generated a CUBE PFM grid for H13341 at 1-meter resolution. SABER populates the CUBE depth with either the node’s chosen hypothesis or the depth of a feature or designated sounding set by the hydrographer, which overrides the chosen hypothesis. The range of CUBE depths of the H13341 1-meter PFM grid were from 0.705 meters (2.313 feet; 0.210 meters Total Vertical Uncertainty [TVU]) to 9.668 meters (31.719 feet; 0.210 meters TVU). The final gridded bathymetry data are delivered as a Bathymetric Attributed Grid (BAG). The BAG file was exported from the CUBE PFM grid as detailed in the DAPR.Additional information discussing the vertical and horizontal control for this survey can be found in the DAPR.Mean Lower Low WaterERS via VDATUMOPR-E350-KR-20_NAD83_VDatum_MLLW.covRefer to the DAPR for details regarding the application of VDatum to the MBES data files. No final tide note was provided nor was it required from NOAA Center for Operational Oceanographic Products and Services (CO-OPS). North American Datum 1983Projected UTM 18The vessel kinematic data (POS/MV files) were post-processed in Applanix POSPac software using the Applanix PP-RTX solution to generate the Smoothed Best Estimate of Trajectory (SBET) solutions which were applied through SABER to the multibeam data. Refer to the DAPR for additional information and for details regarding all antenna and transducer offsets. Any soundings with total horizontal uncertainties exceeding the maximum allowable IHO S-44 5th Edition Order 1a specifications were flagged as invalid and therefore were not used in the CUBE depth calculations.Chart comparisons were conducted using a combination of SABER and CARIS’ HIPS and SIPS. H13341 data met data accuracy standards and bottom coverage requirements. Leidos recommends updating the common areas of all charts using data from this survey. Review showed that the H13341 depth data were generally in good agreement with charted depths on ENC US5VA24M and US5VA26M. Charting recommendations for new features and updates to charted features, are documented in the H13341 S-57 FFF. Additional charted objects are discussed in later sections. United States Coast Guard (USCG) District 5 Local Notice to Mariners (LNM) publications were reviewed for changes subsequent to the date of the Project Instructions and before the end of survey (as specified in Section 8.1.4 of the HSSD). The LNM reviewed were from week 33/20 (18 August 2020) until week 16/21 (20 April 2021). LNM 41/20 (13 October 2020) notes Mobjack Bay Channel Daybeacon 6MB as ‘DAYMK DMGD'; LNM 43/20 (27 October 2020) subsequently notes the daymark as ‘WATCHING PROPERLY’. LNM 06/21 (09 February 2021) lists new obstructions and charted wreck removal which were sourced from H13341 DTON 05 with Anti-DTON and H13341 DTON 06; refer to Section D.1.2 for further information.US5VA24M40000292020-03-242021-03-09US5VA26M40000162019-04-262021-03-23US5VA24M ENC US5VA24M covers the southeastern portion of the H13341 survey limit. CUBE depths within H13341 agreed well with the charted depths across the contemporaneous survey area; observed depths were primarily within ±1 meters of charted depths. The depth contours on ENC US5VA24M showed mixed agreement with depths that fell within the H13341 survey area; several differences were observed with contour boundaries. US5VA26M ENC US5VA26M covers the northwestern portion of the H13341 survey limit. CUBE depths within H13341 agreed well with the charted depths across the contemporaneous survey area; observed depths were primarily within ±1 meter of charted depths. There was greater variability at some points in the Severn River and the Southwest Branch of the Severn River. The depth contours on ENC US5VA26M showed mixed agreement with depths that fell within the H13341 survey area; some differences were observed with contour boundaries. EMThere were no significant shoals or hazardous features within the area covered by this survey other than those referenced in Section D.1.4 and H13341 DTON reports. Leidos submitted nine DTONs for H13341 in S-57 format to the Atlantic Hydrographic Branch (AHB). Details are listed in Figure 8. DTON 01 and DTON 02 were not forwarded by AHB to the Nautical Data Branch (NDB) and Marine Chart Division (MCD) per correspondence from NOAA on 19 October 2020. Features in the H13341 FFF associated with DTON 01 and DTON 02 do not retain the special feature type of DTON. DTON 07 was submitted to the US Coast Guard on 03 March 2021, for an uncharted beacon lateral with daymark signage, in accordance with HSSD Section 1.6.2. Per correspondence with NOAA on 05 March 2021, this feature was also submitted to NOAA as DTON 07, on 17 March 2021. Copies of the email correspondence for Leidos’ submissions of H13341 DTON Report, as well as the DTON recommendation file, are included within Appendix II of this Descriptive Report. Figure 8 details the submitted DTON and the associated Feature number and object class in the S-57 FFF. DTON ReportsSupportFiles\H13341_Figure_08.jpgThere were numerous assigned charted features in the final CSF (OPR-E350-KR-20_CSF.000) within the SOW of H13341; refer to the H13341 S-57 FFF (H13341_FFF.000) for all the details and recommendations regarding these features.See the H13341 S-57 FFF for all the details and recommendations regarding new uncharted features investigated. During the course of H13341 survey operations, various PVC and bamboo pipe markers were observed within the survey limits (Figure 9). These were determined to be temporary in nature as over the course of survey operations it was observed that several of the markers would either no longer be present or would have been moved. Due to their temporary nature, there are no features associated with these markers within the H13341 S-57 FFF. If the markers were confirmed visually to be above water, the MBES data were invalidated. There were instances where in MBES and SSS submerged markers were identified; no features or significant contacts were set for these as they were not warranted in accordance with HSSD. Data remain valid within the MBES. An uncharted dock (Feature 10) was observed within the northwest branch of the Severn River, Figure 10 The majority of the dock was inshore of NALL depths and therefore not fully investigated within H13341; SSS data were acquired on the pilings associated with the dock. One obstruction (Feature 30) was identified in SSS data only. The obstruction was located inshore of NALL depths and thus it was deemed unsafe to obtain MBES data over the object due to water level depths at the time of item investigation.Example of PVC MarkerSupportFiles\H13341_Figure_09.jpgUncharted Dock in Northwest Branch of Severn RiverSupportFiles\H13341_Figure_10.jpgThere were no channels coincident to the H13341 survey limits.There were sixteen assigned aids to navigation (ATON) within the SOW of H13341 from the final CSF. Two of the sixteen assigned ATONs were not investigated due to their location being inshore of NALL depths. The remaining fourteen assigned ATONs were observed on station and serving their intended purpose. Per the investigation requirements from the CSF, as they were on station and serving intended purpose, they are included in the H13341 FFF with description of retain. As discussed in Section D.1.2 an uncharted old beacon lateral with signage (Figure 11) was observed in the Southwest Branch of the Severn River. There was a faded red signage and the post was leaning over in the water. This was reported to USCG by Leidos as an ATON Discrepancy Report and to AHB as a DTON. See the H13341 S-57 FFF for all the details and recommendations regarding the ATONs.Uncharted Old Daymark in Southwest Branch of Severn RiverSupportFiles\H13341_Figure_11.jpgNo Maritime Boundary Points were assigned for this survey.In accordance with both the Project Instructions and Section 7.2.3 of the HSSD, bottom characteristics were obtained for H13341. Bottom characteristics were acquired at six of the seven assigned locations assigned from the final PRF (OPR-E350-KR-20_PRF.000). The proposed location of the seventh bottom sample had a position lying well inshore of NALL depths; as such, Leidos modified the position of the seventh sample to a more suitable location. Bottom characteristics are included in the H13341 S-57 FFF. In addition, images of the sediment obtained for each bottom sample are referenced in the H13341 S-57 FFF and are included on the delivery drive under the folder H13341/Processed/Multimedia.No overhead features exist within this survey area. Four overhead cables were assigned from the CSF, however, were not investigated as they were inshore of the NALL.There were no submarine features (cables, pipelines, or tunnels) charted or identified within this survey area. Refer to the H13341 S-57 FFF for all the details and recommendations regarding featuresNo platforms exist within the limits of this survey area. Three platforms were assigned from the CSF, however, were not investigated as they fell in water depths shoaler than the NALL.No ferry routes or terminals exist within this survey area.No abnormal seafloor or environmental conditions, as defined in Section 8.1.3 of the HSSD, exist within this survey area.No construction or dredging exists for this survey area.No new survey recommendations are made for the area surrounding this survey area.No new ENC recommendations are made for the area surrounding this survey 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.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 Hydrographic Surveys Specifications and Deliverables, Project Instructions, and Statement of Work. These data are adequate to supersede charted data in their common areas. This survey is complete and no additional work is required. Previously, or concurrently, submitted deliverables for OPR-E350-KR-20 are provided in the table below.Erin MarkhamLead Hydrographer2021-04-27OPR-E350-KR-20_Marine_Species_Awareness_Training_Record.pdf2021-04-14OPR-E350-KR-20_20210419.zip (NCEI Sound Speed Data 2020 data only)2021-04-19OPR-E350-KR-20_Coast Pilot Review Report.pdf 2021-04-19OPR-E350-KR-20_DAPR.pdf2021-04-27