OPR-E350-TJ-16Southern Chesapeake BayChesapeake BayNOAA Ship THOMAS JEFFERSONH128661Local constituents have raised concerns over the accuracy of nautical charts in the area, directly affecting their ability to safely navigate. This project will cover approximately 50 square nautical miles. Survey data from this project is intended to supersede all prior survey data in the common area.Willoughby BankVirginiaUnited States100002016Chris van Westendorp, CDR/NOAANavigable Area2016-03-092016-04-042016-08-25Multibeam Echo SounderSinglebeam Echo Sounder Side Scan SonarMultibeam Echo Sounder BackscattermetersUniversal Transverse Mercator (UTM)UTCAtlantic Hydrographic BranchNOAAHydrographic survey H12866 was completed as specified by hydrographic survey project instructions OPR-E350-TJ-16, signed 09 March 2016. This survey extends from Little Creek, VA to Poquoson, VA.37.138922222276.270641666736.933602777876.1891027778H12866 Project Extentsfile:///H:/Surveys/OPR-E350-TJ-16%20Southern%20Chesapeake%20Bay/H12866/Separates/Descriptive_Report/Report/DR%20Images/Extents.pngSurvey H12866, Sheet 1 of OPR-E350-TJ-16 extends from Little Creek in the South to Back River in the North, from Thimble Shoal Channel West to the Hampton Roads Bridge Tunnel (Figure 1). Deviations were made to the original survey limits as assigned. The Chief of Party made the decision to extend the western perimeter of the sheet limits to include Willoughby Bay Channel and the complete extents of the Hampton Roads Bridge Tunnel based on local reports of dangers to navigation, predominantly shoaling (Figure 2). This extension was acquired using a combination of object detection multibeam collected by hydrographic survey launches and singlebeam data collected by an autonomous Z-boat (Figure 3). Two other allowances of sheet limit deviation were made for further extensions: one obstruction on the eastern side of the project area near the entrance to Little Creek that was cut off by sheet limits (Figure 4) and one fish haven along the northernmost edge of the sheet limit (Figure 5). Both areas were fully developed with object detection multibeam data. The project limits were not completed in the vicinity of Phoebus Channel near the northern end of the Hampton Roads Bridge Tunnel due to safety concerns (Figure 6) nor in the northwestern section into Back River due to time and schedule constraints (Figure 7). The southeasterly point of Willoughby Bank also has an area that was not covered by survey data. The area is approximately 100m by 200m (Figure 8). Two areas without data coverage exist along the northern-most limit of the project area (Figures 9 and 10). Five data coverage gaps exist along the eastern sheet limit that are small, and likely the result of early termination of logging data. The most severe of these is located at 37-08-08.835N 076-11-59.597W. The southern edge of the sheet also has some minor data gaps where the side scan sonar imagery does not meet the inshore-most multibeam data (Figure 11). Active Captain markers for local concerns to safe navigation. Western survey limits were extended to include markers 4, 2, and 5.file:///H:/Surveys/OPR-E350-TJ-16%20Southern%20Chesapeake%20Bay/H12866/Separates/Descriptive_Report/Report/DR%20Images/ActiveCaptain.jpgData extends from sheet limits. Surface shown is a 1m interpolated surface of both multibeam and singlebeam data for increased visibility.file:///H:/Surveys/OPR-E350-TJ-16%20Southern%20Chesapeake%20Bay/H12866/Separates/Descriptive_Report/Report/DR%20Images/ExtensionA.pngData extends from sheet limits to cover obstruction.file:///H:/Surveys/OPR-E350-TJ-16%20Southern%20Chesapeake%20Bay/H12866/Separates/Descriptive_Report/Report/DR%20Images/extensionB.pngData extends from sheet limits to cover fish haven.file:///H:/Surveys/OPR-E350-TJ-16%20Southern%20Chesapeake%20Bay/H12866/Separates/Descriptive_Report/Report/DR%20Images/extensionC.pngArea South of Old Point Comfort where survey coverage does not meet sheet limit nor 12ft curve. file:///H:/Surveys/OPR-E350-TJ-16%20Southern%20Chesapeake%20Bay/H12866/Separates/Descriptive_Report/Report/DR%20Images/LackOCov-Hampton.jpgIncomplete northern section of Sheet H12866. file:///H:/Surveys/OPR-E350-TJ-16%20Southern%20Chesapeake%20Bay/H12866/Separates/Descriptive_Report/Report/DR%20Images/LackOCov-BackRiver.jpgData gap South of Willoughby Bank. file:///H:/Surveys/OPR-E350-TJ-16%20Southern%20Chesapeake%20Bay/H12866/Separates/Descriptive_Report/Report/DR%20Images/CoverageGap1WillBank.jpgData gap along northern sheet limit.file:///H:/Surveys/OPR-E350-TJ-16%20Southern%20Chesapeake%20Bay/H12866/Separates/Descriptive_Report/Report/DR%20Images/Ngap1.jpgData gap along northern sheet limit.file:///H:/Surveys/OPR-E350-TJ-16%20Southern%20Chesapeake%20Bay/H12866/Separates/Descriptive_Report/Report/DR%20Images/Ngap2.jpgSSS coverage gaps.file:///H:/Surveys/OPR-E350-TJ-16%20Southern%20Chesapeake%20Bay/H12866/Separates/Descriptive_Report/Report/DR%20Images/angledgaps.jpgLocal constituents have raised concerns over the accuracy of nautical charts in the area, directly affecting their ability to safely navigate. This project will cover approximately 44 square nautical miles. 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.Inshore Limit to 4 meters100 meter Set Line SpacingOffshore Shoals of depths 1-4 meters50 meter Set Line SpacingAll waters non-contiguous to shoreComplete CoverageSurvey H12866 deviated from the coverage requirements in the area adjacent to North of Hampton Roads Channel, South of Thimble Shoal. Coverage in this area was requested by the Chief of Party to be acquired with object detection multibeam. Survey H12866 utilized several different methods of coverage; object detection multibeam in Thimble Shoal Channel and from the channel North to the southern portion of Thimble Shoal, 50m line spaced vertical beam inshore of the 12ft depth curve (Figure 12), and 100% SSS (Figure 13)with concurrent multibeam. Multibeam data was gridded to both 1m and 50cm specifications and vertical beam was gridded to 1m specifications, as opposed to the required 4m grid. There are four occurrences of 200% side scan sonar data acquired to aid in feature disproval, but all were later reacquired with object detection multibeam (Figure 14). The HDCS data, mosaic, and geotiff are included with the submission of this project even though they were not used to prove or disprove feature occurrence. H12866 bathymetric coverage.file:///H:/Surveys/OPR-E350-TJ-16%20Southern%20Chesapeake%20Bay/H12866/Separates/Descriptive_Report/Report/DR%20Images/BathyCoverage.jpgH12866 100% Side Scan Sonar coverage.file:///H:/Surveys/OPR-E350-TJ-16%20Southern%20Chesapeake%20Bay/H12866/Separates/Descriptive_Report/Report/DR%20Images/SSS100Cov.jpgH12866 200% Side Scan Sonar coverage.file:///H:/Surveys/OPR-E350-TJ-16%20Southern%20Chesapeake%20Bay/H12866/Separates/Descriptive_Report/Report/DR%20Images/SSS200Cov.jpg3101092.19000282.28095.38031020621.98000616.73033.970Z-17.080000000.480Z-2193.640000009.980200.72714.17000899.010139.8107.70000044.742016-04-042016-04-062016-04-072016-04-082016-04-112016-04-122016-04-152016-04-182016-04-192016-04-212016-04-222016-04-252016-04-262016-04-272016-04-292016-05-022016-05-032016-05-062016-05-092016-05-102016-05-112016-05-122016-05-132016-05-162016-05-172016-05-202016-05-242016-05-252016-05-262016-05-272016-05-312016-06-022016-06-032016-06-072016-06-092016-06-142016-06-152016-06-162016-06-202016-06-212016-06-242016-07-272016-07-292016-08-042016-08-102016-08-112016-08-152016-08-162016-08-172016-08-182016-08-232016-08-242016-08-25Refer 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.HSL 3101315.2HSL 3102315.2Z-15.51Z-25.51Data was acquired by 3101, 3102, Z1, and Z2. The four platforms collected Reson multibeam echosounder soundings, singlebeam echosounder soundings, multibeam backscatter data, side scan sonar imagery, sound velocity profiles, surface sound speed readings, and position and attitude data.Reson7125 SV2MBESKlein5000 V1SSSOdomEchotrac CV100SBESApplanix Applanix M/V v4Positioning and Attitude SystemSeabirdSeacat 19+Conductivity, Temperature, and Depth SensorTrimbleSPS461Positioning SystemResonSV-70Sound Speed SystemThe Thomas Jefferson hydrographic survey launches and autonomous survey vessels collected 139.81 linear nautical miles of MBES and VBES crosslines, equating to 7.71% of mainscheme MBES and VBES data. As section 5.2.4.3 of the 2016 HSSD outlines, combined vertical beam and multibeam crossline mileage for mixed echosounder set line spacing surveys must meet the minimum requirement of 8% of mainscheme mileage. Survey H12866 does not meet this specification. Crosslines were compared to mainscheme by differencing a 1m resolution mainscheme surface to a 1m resolution crossline surface in CARIS BASE Editor 4.2. 99.97% of differenced nodes agree within 0.5m. The mean was 0.0m and the standard deviation was 0.1m (Figure 15). The large values of minimum and maximum differences of -3.2m and 2.9m respectively, stem from areas of high relief such as the northern fish haven. The difference surface was filtered to specifically examine the locations of values from -3.2m to -0.49m and 0.49m to 2.9m. No outstanding or systemic errors were noted in the data. Results of surface differencing between mainscheme and crossline surfaces. file:///H:/Surveys/OPR-E350-TJ-16%20Southern%20Chesapeake%20Bay/H12866/Separates/Descriptive_Report/Report/DR%20Images/diffXLs_MS.jpg00.092ERS via VDATUM3101400.23102400.2Z-1400.2Z-2400.2Total Propagated Uncertainty values for survey H12866 were derived using a combination of: real time uncertainties for vessel motion; a priori values for equipment and vessel characteristics; an a priori value for the separation model used to reduce soundings to chart datum; and field assigned values for sound speed uncertainties. The realtime uncertainties for vessel motion include roll, pitch, gyro, navigation, and elevation. The uncertainties in these measurements were recorded as part of the POSPac Real Time Kinematic position solution, as well as the POSPac smartbase IAPPK solution, and were applied to the soundings via an SBET RMS file generated by Applanix POSPac 7.2. Uncertainties for sonar mounting and vessel speed were based on Appendix 4, table 4.9 of the NOAA Field Procedures Manual (ed 2014). These uncertainties were applied to the data via the CARIS HIPS Vessel File. The uncertainty associated with the VDatum separation model was supplied by the Hydrographic Surveys Division’s Operations Branch, and is listed under Zoning (Table 6). Finally, the uncertainty associated with sound speed measurements was based on the frequency and location of CTD casts, in accordance with the guidance set by Appendix 4 of the FPM (ed2014) (Table 7). Total Propagated Uncertainty was then evaluated to ensure compliance with section 5.1.3 of NOAA's Hydrographic Surveys Specifications and Deliverables. First, the maximum allowable uncertainty for each node was calculated using the equation: -Uncertainty/((0.5^2+((Depth*0.013)^2))^0.5). Second, the ratio between actual uncertainty and maximum allowed uncertainty was found for each node. The resulting 'TVU_QC' layer was filtered using a color map to show any areas where actual uncertainty exceeded the maximum allowed uncertainty. Additionally the Pydro CSAR QA tool was utilized for each surface to be submitted. For grid H12866_MB_50cm_MLLW_Final.csar, 99.9% of nodes passed uncertainty standards (Figure 16). 15 nodes out of 222,903,224 exceed allowable TVU tolerances. All nodes out of TVU allowance are confined to an area around the Hampton Roads Bridge Tunnel at 36-59-35.584 N and 076-18-39.893 W (Figure 17). These were reviewed, and the excessive uncertainty appears to be associated mainly with the slopes of 1-2m bedforms in that locale. Refraction error associated with sound velocity profiles may also be a minor contributor. The 50cm gridded surface appears to be unaffected and shows no sign of honoring the outlying nodes. For grid H12866_MB_1m_MLLW_Final.csar, 99.9% of nodes passed uncertainty standards (Figure 18). 2,663 nodes out of 3,122,257 million exceed allowable TVU tolerances. Most of these nodes are confined to the area south of Old Point Comfort in and along the periphery of Thimble Shoal Channel. These were reviewed, and the excessive uncertainty appears to be associated mainly with refraction error associated with sound velocity profiles. As seen in Figures 19 and 20, sound velocity profile depths for this day did not extend to the deepest bathymetry collected and is at the root of the TVU bust. H12866_MB_50cm_MLLW_Final Uncertainty Standards statistics utilizing Pydro CSAR QA.file:///H:/Surveys/OPR-E350-TJ-16%20Southern%20Chesapeake%20Bay/H12866/Separates/Descriptive_Report/Report/DR%20Images/H12866_MB_50cm_MLLW_FINAL.tvu_qc.pngArea of grid nodes exceeding allowable TVU for H12866_MB_50cm_MLLW.file:///H:/Surveys/OPR-E350-TJ-16%20Southern%20Chesapeake%20Bay/H12866/Separates/Descriptive_Report/Report/DR%20Images/50cmSurfTVUexceeds.jpgH12866_MB_1m_MLLW_Final Uncertainty Standards statistics utilizing Pydro CSAR QA.file:///H:/Surveys/OPR-E350-TJ-16%20Southern%20Chesapeake%20Bay/H12866/Separates/Descriptive_Report/Report/DR%20Images/H12866_MB_1m_MLLW_FINAL.tvu_qc.pngArea of grid nodes exceeding allowable TVU for H12866_MB_1m_MLLW.file:///H:/Surveys/OPR-E350-TJ-16%20Southern%20Chesapeake%20Bay/H12866/Separates/Descriptive_Report/Report/DR%20Images/1mSurfTVUexceeds.jpgDeepest sound velocity profile from HSL 3101 on DN127 (<20m) applied to data with depths greater than 30m. file:///H:/Surveys/OPR-E350-TJ-16%20Southern%20Chesapeake%20Bay/H12866/Separates/Descriptive_Report/Report/DR%20Images/1mSurfTVUexceedsSVP.jpgNo contemporary junction surveys exist in the area of H12866.Sonar system quality control checks were conducted as detailed in the quality control section of the DAPR.None ExistThere were no conditions or deficiencies that affected equipment operational effectiveness.None ExistThere were no other factors that affected corrections to soundings.Approximately every 4 hoursCTD casts performed by launches 3101 & 3102 were taken at a maximum of 4 hour intervals; or more frequently in areas where sound speed changed by greater than 2m/sec. If 3101 or 3102 was tending either Z-1 or Z-2, the launch would take a singlebeam specific cast and apply it to the proper ASV's master sound velocity file. Figure 21 shows acquired data colored by sound velocity cast. H12866 geographic distribution of sound velocity casts from 3101 and 3102.file:///H:/Surveys/OPR-E350-TJ-16%20Southern%20Chesapeake%20Bay/H12866/Separates/Descriptive_Report/Report/DR%20Images/H12866_SVP.jpgRefer to section A.4 and B.1.2 of this report for survey equipment and methods used to meet coverage requirements for this project.Outer Beam FilteringHydrographic Survey Launch 3101 data exhibited high uncertainty in the outer beams, as data was collected at maximum swath angle. A filter was created in CARIS 9.1 HIPS to reject all data greater than 65 degrees from nadir for both port and starboard beams in the bulk of the multibeam data collected by 3101. Ultimately, the overall mean uncertainty values for the survey were lowered by a significant amount after filtering was applied. All data reduction procedures conform to those detailed in the DAPR.All sounding systems were calibrated as detailed in the DAPR.Raw backscatter was logged as a 7k file and was processed by the field unit. A backscatter project was created for each vessel and will be submitted as a deliverable with this report. CarisHIPS and SIPS9.1.2FledermausFMGT7.6.4NOAA Profile V_5_4H12866_MB_50cm_MLLW_FINALCUBE0.50.8120.00NOAA_0.5mComplete MBESH12866_MB_1m_MLLW_FINALCUBE117.5931.26NOAA_1mObject DetectionH12866_VB_1m_MLLW_FINALCUBE1-0.8016.58NOAA_1mMBES TracklineSBES Set Line SpacingH12866_SSS_100_1mSSS Mosaic100N/A100% SSSH12866_SSS_200_1mSSS Mosaic100N/A200% SSSSubmitted multibeam grids for survey H12866 exceed the full coverage requirements assigned by the project instructions. Both the 1m and 50cm surfaces meet object detection requirements for density as described in section 5.2.2.2 of the HSSD 2016 (Figures 22 and 23). For further discussion, see section A.4 of this report. 98.7% of H12866_MB_50cm_MLLW_FINAL passes density requirements for object detection multibeam. file:///H:/Surveys/OPR-E350-TJ-16%20Southern%20Chesapeake%20Bay/H12866/Separates/Descriptive_Report/Report/DR%20Images/H12866_MB_50cm_MLLW_FINAL.density.png99.5% of H12866_MB_1m_MLLW_FINAL passes density requirements for object detection multibeam. file:///H:/Surveys/OPR-E350-TJ-16%20Southern%20Chesapeake%20Bay/H12866/Separates/Descriptive_Report/Report/DR%20Images/H12866_MB_1m_MLLW_FINAL.density.pngSurvey Lines With No Delayed Heave Several lines of multibeam data exist within survey H12866 that have no associated delayed heave. Lines from launch 3101 missing delayed heave are: 118_138_1459, 161_388_1429, 209_301_1734, 209_347_1835, and 228_316_1632. Lines from launch 3102 missing delayed heave are: 145_319_1337, 145_322_1426, 145_320_1408, 145_318_1320, 145_321_1352, 172_224_1823, and 166_401_1405. Hypothetically, there is a correlation between line length and the ability to incorporate delayed heave data into the line information. Message from CARIS: "WARNING: Delayed heave was selected for the above lines, but no data was found. Only heave has been applied". The Hydrographer assesses the effect on data collected for which there is no delayed heave applied appears to be negligible. The autonomous survey vessels used to acquire vertical beam data have no heave sensor, and therefore, no heave data. Positioning correctors applied to verticalbeam data are derived from a Real Time Kinematic solution. Surface FliersH12866_MB_1m_MLLW_FINAL grid scanned for fliers at 50cm tolerance yielded 18 potential fliers. After review and directed editing, remaining flagged nodes were determined to be valid objects. H12866_MB_50cm_MLLW_FINAL grid scanned for fliers at 50cm tolerance yielded 2526 potential fliers. 2475 of these exist within two fish havens expected to have significant relief. 2381 are located within the northernmost fish haven, 76 are located in the southern fish haven. The remaining 69 flagged fliers were reviewed and deemed valid objects. H12866_VB_1m_MLLW_FINAL grid scanned for fliers at 50cm tolerance yielded 0 potential fliers. Several of the initially flagged fliers were particularly difficult to identify as the flier itself could only be observed in the 3-D subset view and not 2-D subset. CARIS HIPS 9.1.2 is unable to resolve some isolated surface areas in 2-D subset and reviewers should be aware of this bug. Additional information discussing the vertical or horizontal control for this survey can be found in the accompanying HVCR.Mean Lower Low WaterKiptopeke8632200Yorktown8637689Sewells Point8638610Chesapeake Bay Bridge Tunnel8638863TCARI8662200.tidFinal Approved8637689.tidFinal Approved8638610.tidFinal Approved8638863.tidFinal ApprovedE350TJ2016.tcFinal2016-08-302016-09-13ERS via VDATUMOPR-E350-TJ-16_ExtendedSEPWGS8418NSmart BaseA RTK base station was installed on top of the Atlantic Hydrographic Branch in Norfolk, VA. For further information, reference the accompanying HVCR with this report. Surveyed soundings were compared to existing charted soundings by two separate methods to ensure agreement in results. The first method differenced surveyed soundings to to an interpolated grid of existing ENC soundings in BASE Editor 4.2. The second method utilized exported ASCII data, both surveyed soundings and ENC soundings, from BASE Editor 4.2 and assessed comparison of surveyed soundings to charted soundings. The areas of greatest change were then flagged in a feature layer populated with cartographic symbols. The resultant generalized cartographic symbol layer accurately portrayed areas of shoaling and significant change, while the most significant difference points and areas (most likely to be dangers to navigation, or DtoNs) were flagged in a separate layer. The area encompassed within survey H12866 showed relative stability to previously charted data. However, areas of shifting shoals pose dangers throughout, as noted in the Danger to Navigation Reports located in Appendix II and submitted with this report. Both methods of assessing changes to charted bathymetry resulted in a good visual representation of change. In the area immediately South of Thimble Shoal Light, a shoal has developed with depths ranging up to 9m shoal to charted soundings. It appears a south easterly shift in Thimble Shoal is the primary contributor to this accretion (Figure 24). The United States Army Corps of Engineers, Norfolk District has scheduled dredging this area for early 2017 and will be using the removed material to renourish the beach along bay-side sections of Willoughby Spit (ref Appendix II of this report). The easternmost reach of Willoughby Bank has shifted southeast by approximately 140m, taking along with it the shoalest of the charted soundings (Figure 25). This shift resulted in the submission of DtoN Report 1, which can be found in Appendix II of this report. At the time this report was submitted, the effected charts have been updated with the instance of shoaling described in DtoN Report 1. Another significant occurrence of shoaling has developed in the vicinity of 36-59-27.525N 076-17-38.990W. A surveyed sounding of 15ft was found in the vicinity of a 22ft charted sounding (Figure 26). This was determined not to be a danger to navigation. Other significant areas of shoaling have occurred along the southern portion of the Hampton Roads Bridge Tunnel in the vicinity of Fort Wool. Willoughby Channel, to the West, is known to have dangerous shoaling around 36-58-52.166N 076-18-38.438W (Figure 27). Shoaling was reported in DtoN Report 1 found in Appendix II of this report. A supplementary Aid to Navigation had been placed prior to this survey, and the charted depth curve has been updated to reflect this change, but danger of grounding still exists. At the time this report was submitted, the effected charts have been updated with the instance of shoaling described in DtoN Report 1. On the North end of the Hampton Roads Bridge Tunnel and along the shoreline of Old Point Comfort, surveyed depths are shoal to charted soundings on the magnitude of 2-5m (Figure 28). In the northern section of the survey, shoals have shown general eastward movement on the magnitude of 75m to 140m from charted positions (Figure 29). Two dangers to navigation were submitted in this area: DtoN Report 3 and DtoN Report 5 (Appendix II). DtoN 3 exists at 57-06-14.186N 076-15-12.590W where a 2ft sounding was surveyed 120m outside of the charted 6ft contour, in between a 19ft and and 18ft charted sounding (Figure 30). DtoN 5 is within the Back River Channel where shoaling is threatening the safe passage of the channel (Figure 31). At the time this report was submitted, the effected charts have been updated with the instances of shoaling described in both DtoN Report 3 and DtoN Report 5. Both large fish havens within the survey limits have depths shoal to charted authorized minimum depths. Two DtoNs were submitted from surveyed depths within the northern fish haven: DtoN 2 and DtoN 4. DtoN 2 is a pile of debris with a least depth of 8ft; DtoN 4 is a pile of debris with a least depth of 11ft (Figure 32). At the time this report was submitted, the effected charts have been updated with the instances of shoaling described in both DtoN Report 2 and DtoN Report 4. In the southern fish haven, one debris pile exceeds authorized minimum by less than 0.5ft. An uncharted shipwreck with a least depth of 21.59ft exists along the northern border of the fish haven (Figure 33). As the shoals have shifted, so too have the deeps. In general, as the faces of the shoals have shifted eastward the surveyed depths behind them now read deep to the charted soundings. Two areas found to be deeper than charted are: an area of scour under the Hampton Roads Bridge Tunnel (possibly due to construction work on the tunnel) and an area where sand has been physically removed for beach renourishment 3km East of Buckroe Beach. With the exception of the shoaling and other objects noted above, the bathymetry of survey H12866 agrees well with existing charted information. For further analysis of charted and new features, refer to the Final Feature File submitted with this report.Thimble Shoal has shifted in a southeasterly direction causing a mass of sand to accrete in the vicinity of Thimble Shoal Light. This area will be a material source for a beach renourishment project undertaken by the USACE in early 2017. file:///H:/Surveys/OPR-E350-TJ-16%20Southern%20Chesapeake%20Bay/H12866/Separates/Descriptive_Report/Report/DR%20Images/ThimbleShoalShoaling.jpgShifting shoal of Willoughby Bank.file:///H:/Surveys/OPR-E350-TJ-16%20Southern%20Chesapeake%20Bay/H12866/Separates/Descriptive_Report/Report/DR%20Images/Willoughby.jpgShoaling along northern Willoughby Bank and the southern section of the Hampton Roads Bridge Tunnel.file:///H:/Surveys/OPR-E350-TJ-16%20Southern%20Chesapeake%20Bay/H12866/Separates/Descriptive_Report/Report/DR%20Images/FtWool.jpgShoaling in Willoughby Channel. Dangerous encroachment of sediment into channel is highlighted in red circle . Aid to Navigation was placed before current survey and is on station serving its intended purpose. file:///H:/Surveys/OPR-E350-TJ-16%20Southern%20Chesapeake%20Bay/H12866/Separates/Descriptive_Report/Report/DR%20Images/WilloughbyBayChan.jpgShoaling noted along the North end of the Hampton Roads Bridge Tunnel and along the southern edge of Old Point Comfort. file:///H:/Surveys/OPR-E350-TJ-16%20Southern%20Chesapeake%20Bay/H12866/Separates/Descriptive_Report/Report/DR%20Images/ShoalingOldPtComf.jpgGeneral eastward movement of charted shoals in the vicinity of Back River including 2 DtoNs.file:///H:/Surveys/OPR-E350-TJ-16%20Southern%20Chesapeake%20Bay/H12866/Separates/Descriptive_Report/Report/DR%20Images/ShiftingShoalsNorth.jpgDanger to Navigation number 3. Surveyed 2ft sounding 120m East of nearest 5ft contour. file:///H:/Surveys/OPR-E350-TJ-16%20Southern%20Chesapeake%20Bay/H12866/Separates/Descriptive_Report/Report/DR%20Images/DtoN3.jpgDanger to Navigation number 5. Shoaling is encroaching into Back River Channel. file:///H:/Surveys/OPR-E350-TJ-16%20Southern%20Chesapeake%20Bay/H12866/Separates/Descriptive_Report/Report/DR%20Images/DtoN5.jpgNorthern fish haven with authorized minimum of 15ft. Current survey found 3 soundings shoal to authorized minimum, 2 of which were reported as DtoNs. file:///H:/Surveys/OPR-E350-TJ-16%20Southern%20Chesapeake%20Bay/H12866/Separates/Descriptive_Report/Report/DR%20Images/FishHavenN.jpgThe southern fish haven has one debris pile with a least depth of 19.69ft. There is also an uncharted ship wreck just beyond the northern boundary of the fish haven with a least depth of 21.59ft. file:///H:/Surveys/OPR-E350-TJ-16%20Southern%20Chesapeake%20Bay/H12866/Separates/Descriptive_Report/Report/DR%20Images/FishHavenS.jpg12222140000552015-022016-11-102016-11-10NOAA RNC 12222 covers the entire area of survey H12866 at a scale of 1:40000. Any changes to assigned features derived from the ENC can be found in the Final Feature File included with this report. For a general description of bathymetric changes, refer to section D.1 of this report. 12254120000502016-052016-11-122016-11-12NOAA RNC 12254 covers the southeastern area of survey H12866 at a scale of 1:20000. Any changes to assigned features derived from the ENC can be found in the Final Feature File included with this report. For a general description of bathymetric changes, refer to section D.1 of this report.12245120000682013-052016-11-122016-11-12NOAA RNC 12245 covers the southwestern area of survey H12866 at a scale of 1:20000. Any changes to assigned features derived from the ENC can be found in the Final Feature File included with this report. For a general description of bathymetric changes, refer to section D.1 of this report.US5VA13M40000352016-09-272016-11-27falseNOAA ENC US5VA13M covers the northern area of survey H12866 from Buckroe Beach to Back River at a scale of 1:40000. Any changes to assigned features derived from the ENC can be found in the Final Feature File included with this report. For a general description of bathymetric changes, refer to section D.1 of this report.US5VA15M20000452016-08-112016-08-11falseNOAA ENC US5VA15M covers the southwestern area of survey H12866 at a scale of 1:20000. Any changes to assigned features derived from the ENC can be found in the Final Feature File included with this report. For a general description of bathymetric changes, refer to section D.1 of this report. US5VA18M5000152016-07-202016-07-20falseNOAA ENC US5VA18M covers a small area of survey H12866 in the vicinity of Little Creek at a scale of 1:5000. Any changes to assigned features derived from the ENC can be found in the Final Feature File included with this report. For a general description of bathymetric changes, refer to section D.1 of this report.US5VA20M20000142016-07-202016-07-20falseNOAA ENC US5VA20M covers the southeastern area of survey H12866 at a scale of 1:20000. Any changes to assigned features derived from the ENC can be found in the Final Feature File included with this report. For a general description of bathymetric changes, refer to section D.1 of this report. US5VA24M40000252016-11-072016-11-07falseNo Maritime Boundary Points were assigned for this survey. Survey H12866 encompassed several obstructions and wrecks with the designation of PA, ED, PD, or Rep. For full details, see the Final Feature File submitted with this report. For full details, see the Final Feature File submitted with this report. 5Danger to Navigation Reports are included in Appendix II of this report. For full details, see the Final Feature File submitted with this report. For full details, see the Final Feature File submitted with this report. No bottom samples were required for this survey.Shoreline was not assigned in the Hydrographic Survey Project Instructions or Statement of Work.Prior survey comparisons exist for this survey, but were not investigated.All Aids to Navigation within the sheet limits of survey H12866 were found to be on station and serving their intended purpose. No overhead features exist for this survey. For full details, see the Final Feature File submitted with this report. No ferry routes or terminals exist for this survey.No platforms exist for this survey. For full details, see the Final Feature File submitted with this report. Present and/or planned construction or dredging exists within the survey limits. The easternmost point of Thimble Shoal will be dredged in early 2017 by the USACE and material used to renourish Willoughby beaches. There is on-going construction and maintenance on the HRBT. The area of Back River that was not completed during this survey should be prioritized for placement in the assignment queue. No new insets 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 and Specifications Deliverables Manual, 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.Chris van Westendorp, CDR/NOAAChief of Party2016-12-12Matthew R. Forrest, LT/NOAAField Operations Officer2016-12-12Allison C StoneSenior Survey Technician2016-12-12