OPR-D302-TJ-15Chincoteague InletCoastal VirginiaNOAA Ship THOMAS JEFFERSONH128564 Approach to Chincoteague Inlet VirginiaUnited States100002015Shepard M. Smith, CAPT/NOAANavigable Area2015-12-042015-12-072015-12-16Multibeam Echo SounderSinglebeam Echo Sounder Side Scan SonarMultibeam Echo Sounder BackscattermetersUniversal Transverse Mercator (UTM)UTCAtlantic Hydrographic BranchNOAASurvey H12856 was conducted in the Coastal Virginia waters in the Approach to Chincoteague Inlet.37.897395555675.408046944437.848546666775.2659561111H12856 Survey Limits overlaid on RNC 12210.file:///H:/Surveys/OPR-D302-TJ-15/H12856/Data/Separates/Descriptive_Report/DR%20Multimedia/H12856_Coverage_Limits.jpgSurvey H12856 consolidated sheet H12855 into its survey limits. This was done to more easily collect and package the data for the investigations of sheet H12855, since its limits resided within H12856 limits. Sheet H12856 absorbed approximately 1.75 square miles of the northern portion of sheet H12854 to allow survey vessel S222 safe maneuvering near the shoals present at the junction of sheets H12856 and H12854. Additionally, the entirety of sheet H12856 survey limits were not surveyed per project instructions due to time constraints, hazardous conditions not accessible by survey vessels, and lack of proper survey equipment by survey platforms aboard S222. H12855 Survey limits consolidated into H12856 overlaid on RNC 12210.file:///H:/Surveys/OPR-D302-TJ-15/H12856/Data/Separates/Descriptive_Report/DR%20Multimedia/H12855_Coverage_Limits.jpgArea of H12854 absorbed by H12856. Approximately 1.75 square miles.file:///H:/Surveys/OPR-D302-TJ-15/H12856/Data/Separates/Descriptive_Report/DR%20Multimedia/Junction_2_H12856_H12854_absorbed.jpgSurvey data from this project is intended to supersede all prior survey data in the common area. Hydrographic holdings in this area date back to 1930 and prior. Local constituents have raised concern over the accuracy of this data and the ability to safely navigate. In addition, lidar analysis has shown significant shoal movement in shallow areas and cause concern that this is occurring in deeper stretches. This project will cover approximately 86 square nautical miles of navigationally significant area as identified in the 2012 NOAA Hydrographic Survey Priorities (NHSP).The entire survey is adequate to supersede previous data.Although the entirety of the sheet limits were not surveyed, all data collected are adequate to supersede previous data due to the inaccuracy of previous charts and the long time span between surveys conducted.Inshore limit to 4 meters water depth100m Set line spacing. Indications of shoaling falling between set line spacing main scheme lines must be investigated. Set line spacing orientation should be approximately perpendicular to countours whenever possible. Refer to HSSD Section 5.2.2.3Greater than 4 meters water depthComplete Coverage accomplished using either: A) Complete coverage MBES depth and backscatter data, or B) 100% SSS coverage with concurrent set line spacing MBES depth and backscatter data. Refer to HSSD Section 5.2.2.2 Survey H12856 exceeded the specifications set by the Project Instructions by utilizing an 80 meter set line spacing for all vessels in waters less than 4 meters in depth, rather than utilizing the minimum 100 meter line spacing defined in the Project Instructions. This allowed for a tighter coverage over shallow areas, more easily defining where additional coverage was needed. This also allowed for the survey launches to acquire side scan sonar with concurrent multibeam data at a 50 meter range scale with proper overlap. Survey H12856 was approached as a highly dynamic and virtually unknown area. Due to the date of the last survey, shifting shoals and various natural hazards, the field ran exploration lines collected by the two launches spaced at 160 meters. Once areas were expanded upon and evaluated by priority determined by the Chief Scientist, the vessels collected data at 80 meter line spacing at minimum. Due to operational, environmental, and temporal constraints, however, not all exploratory lines were filled with the minimum 80 meter lines spacing. Regardless of the completion of the 100% set line spacing data, it is recommended that all H12856 survey data supersede existing chart information.Area coverage specifications. 40 meters vertical beam line spacing, junctioning 80 meter multi beam data.file:///H:/Surveys/OPR-D302-TJ-15/H12856/Data/Separates/Descriptive_Report/DR%20Multimedia/exceeding_coverage.jpg80 meter line spacing utilized inshore of the 12 foot contour.file:///H:/Surveys/OPR-D302-TJ-15/H12856/Data/Separates/Descriptive_Report/DR%20Multimedia/Spec_line_spacing_1.jpgCentral portion of Chinctogeaue Inlet with partial coverage.file:///H:/Surveys/OPR-D302-TJ-15/H12856/Data/Separates/Descriptive_Report/DR%20Multimedia/Partial_coverage_1.jpgWestern portion Chinctogeaue Inlet with partial coverage.file:///H:/Surveys/OPR-D302-TJ-15/H12856/Data/Separates/Descriptive_Report/DR%20Multimedia/Partial_coverage_2.jpgSoutheast portion outer Chinctogeaue Inlet with partial coverage.file:///H:/Surveys/OPR-D302-TJ-15/H12856/Data/Separates/Descriptive_Report/DR%20Multimedia/Partial_coverage_3.jpgH12856 total coverage area.file:///H:/Surveys/OPR-D302-TJ-15/H12856/Data/Separates/Descriptive_Report/DR%20Multimedia/H12856_Coverage_Limits_2.jpgVB data approximately 4.5 nautical miles East of Assateague Beach, absorbed from sheet H12855.file:///H:/Surveys/OPR-D302-TJ-15/H12856/Data/Separates/Descriptive_Report/DR%20Multimedia/H12856_Coverage_Limits_3.jpg310100.52000132.9107.8403102011.7100028.71000Z-117.840000004.040Z-233.950000003.70051.7912.23000161.62015.580670009.792015-12-082015-12-092015-12-102015-12-112015-12-122015-12-132015-12-142015-12-152015-12-16Refer 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.3101315.23102315.2Z-15.51.0Z-25.51.0Data was acquired by 3101, 3102, Z-1 and Z-2. 3101 and 3102 collected Reson multibeam echosounder soundings, multibeam backscatter data; side scan sonar imagery, sound velocity profiles, surface sound speed readings, and position and attitude data. Z-1 and Z-2 collected Odom Verticalbeam data and position data.Reson7125-SV1MBESReson7125-SV2MBESOdomCV100SBESKlein5000 v1SSSApplanixPOS MV v4Positioning and Attitude SystemTrimbleSP351 DGPS BeaconPositioning SystemSeabirdSBE 19+Conductivity, Temperature, and Depth SensorReson SV-70Sound Speed SystemResonSV-71Sound Speed SystemVessel configurations, equipment operations, and data acquisition & processing were consistent with specifications described in the DAPR.ASVs Z-1 and Z-2 collected 14.9% in crosslines against their own vertical beam data. Survey launch 3101 collected 4.5 % in crosslines against its own data. 3102 did not collected crosslines due to time constraints, as well as its primary use as a launching and tending platform for Z-Boat operations. In all, crosslines acquired for this survey totaled 6.0% of mainscheme acquisition. Crosslines were compared to mainscheme using finalized difference surfaces at their pertaining resolutions, created in CARIS HIPS & SIPS. Vertical beam data was compared using surfaces H12856_VB_4m_MLLW_XL_Finalized.csar and H12856_VB_4m_MLLLW_Finalized.csar. A total of 99.9% of 4,991 of nodes were within 0.33 m of each other. Multibeam data was compared using surfaces H12856_MB_1m_MLLW_XL_Finalized.csar and H12856_MB_1m_MLLW_Finalized.csar. A total of 99.9% of 576,491 nodes were within 0.33 m of each other.H12856 Vertical Beam crossline vs. mainscheme difference statistics.file:///H:/Surveys/OPR-D302-TJ-15/H12856/Data/Separates/Descriptive_Report/DR%20Multimedia/H12856_VB_4m_XL_MS_Diff_Stats.jpgH12856 Multibeam crossline vs. mainscheme difference statistics. file:///H:/Surveys/OPR-D302-TJ-15/H12856/Data/Separates/Descriptive_Report/DR%20Multimedia/H12856_MB_1m_XL_MS_Diff_Stats.jpg00.09VDATUM00TCARI31014.0N/A0.231024.0N/A0.2Z-14.0N/A0.2Z-24.0N/A0.2Total Propagated Uncertainty values for survey H12856 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 Marinestar 5P 3D positional solution, as well as the POSPac Marinestar IAPPK solution, and were applied to the soundings via an SBET RMS file generated by Applanix POSPac. Uncertainties for sonar mounting and vessel speed were based on Appendix 4, table 4.9 of the NOAA Field Procedures Manual (FPM) (ed 2014). These were applied to the data via the CARIS HIPS Hydrographic Vessel File. The uncertainty associated with the VDatum separation model was supplied by the Hydrographic Services Division’s Operations Branch, and is listed under the Zoning (see Table 6). Finally, the uncertainty associated with sound speed measurements were based on the frequency and location of CTD casts, in accordance with the guidance set by Appendix 4 of the FPM (ed 2014) (see Table 7). Total Propagated Uncertainty was then evaluated to ensure compliance with section 5.1.3 of NOAA's Hydrographic Survey Specification and Deliverables (HSSD). 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 is 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 Finalized CSAR QA tool was utilized for each surface to be submitted. For H12856_MB_1m_MLLW_Final.csar, 100% of 12,553,976 nodes passed uncertainty standards. For H12856_MB_50cm_MLLW_Final.csar, 100% of 1,559,736 nodes passed uncertainty standards. For H12856_VB_4m_MLLW_Final.csar, 98.4% of 32,549 nodes passed uncertainty standards. Areas of high uncertainty, visible on surfaces H12856_MB_1m_MLLW_Finalized and H12856_Combined_4m_MLLW_Finalized, arise mostly in the outer beams on lines run as set line spacing. development areas, as well as days which positioning was processed and applied utilizing Fugro Marinestar 5p solutions. H12856_MB_1m_MLLW_Finalized_TVU_QC uncertainty standards utilizing Pydro Finalized CSAR QA.file:///H:/Surveys/OPR-D302-TJ-15/H12856/Data/Separates/Descriptive_Report/DR%20Multimedia/H12856_MB_1m_MLLW_Finalized_TVU_QC.pngH12856_MB_50cm_MLLW_Finalized_TVU_QC uncertainty standards utilizing Pydro Finalized CSAR QA.file:///H:/Surveys/OPR-D302-TJ-15/H12856/Data/Separates/Descriptive_Report/DR%20Multimedia/H12856_MB_50cm_MLLW_Finalized_TVU_QC.pngH12856_VB_4m_MLLW_Finalized_TVU_QC uncertainty standards utilizing Pydro Finalized CSAR QA.file:///H:/Surveys/OPR-D302-TJ-15/H12856/Data/Separates/Descriptive_Report/DR%20Multimedia/H12856_VB_4m_MLLW_Finalized_TVU_QC.pngArea in North exhibiting high uncertainty was run as a search development. Area in South is a development of submerged piles utilizing a 5P solution.file:///H:/Surveys/OPR-D302-TJ-15/H12856/Data/Separates/Descriptive_Report/DR%20Multimedia/Uncertainty.jpgLines exhibiting high uncertainty in the outer beams. Area in the South is a development over an unknown object utilizing a 5P solution.file:///H:/Surveys/OPR-D302-TJ-15/H12856/Data/Separates/Descriptive_Report/DR%20Multimedia/Uncertainty_2.jpgOne contemporary survey, H12854, junctions H12856. Two historic surveys, H12094 and H12092, conducted in 2009, junction H12856.Survey junctions to H12856.file:///H:/Surveys/OPR-D302-TJ-15/H12856/Data/Separates/Descriptive_Report/DR%20Multimedia/Junctions_1.jpgH12092200002009SAICSAlthough sheet H12092 does junction with a small portion of H12856, no comparison is available. Due to time constraints and the distance from the high priority area of the inlet no survey data was collected in that area.H12856 junction area to H12092.file:///H:/Surveys/OPR-D302-TJ-15/H12856/Data/Separates/Descriptive_Report/DR%20Multimedia/Junctions_4_H12092.jpgH12094200002009SAICEThe difference between H12856 and H12094 ranged from -3.3 m to 2.3 m with a mean of 0.2 m and a standard deviation of 0.6 m. 64.2% of 65,744 nodes were within 0.33 m of each other. This low percentage is most like due to the 6 year difference in survey dates in such a dynamic area.H12856 junction area to H12094.file:///H:/Surveys/OPR-D302-TJ-15/H12856/Data/Separates/Descriptive_Report/DR%20Multimedia/Junctions_2_H12094.jpgDifference statistics comparing H12856 to H12094.file:///H:/Surveys/OPR-D302-TJ-15/H12856/Data/Separates/Descriptive_Report/DR%20Multimedia/junction_stats_H12856_H12094.jpgH12854100002015NOAA Ship THOMAS JEFFERSONSEThe difference between survey H12856 and H12854 ranged from -2.424 m to 2.106 m with a mean of 0.028 m and a standard deviation of 0.103 m. 99.9% of 266,520 nodes were within 0.33 m of each other. The wide range of vertical differences between H12856 and H12854 arises over a development conducted by both vessels. In H12856 junction area to H12854.file:///H:/Surveys/OPR-D302-TJ-15/H12856/Data/Separates/Descriptive_Report/DR%20Multimedia/Junctions_3_H12854.jpgDifference statistics comparing H12856 to H12854.file:///H:/Surveys/OPR-D302-TJ-15/H12856/Data/Separates/Descriptive_Report/DR%20Multimedia/junction_stats_H12856_854.jpgArea of greatest vertical difference between H12856 & H12854.file:///H:/Surveys/OPR-D302-TJ-15/H12856/Data/Separates/Descriptive_Report/DR%20Multimedia/junction_stats_H12856_854_2.jpgDevelopment over same object by 3102 for H12856 and S222 for H12854. file:///H:/Surveys/OPR-D302-TJ-15/H12856/Data/Separates/Descriptive_Report/DR%20Multimedia/junction_stats_H12856_854_3.jpgSonar 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.Sea States EffectsSurvey day number 345 for vessel 3101 exhibits sound velocity artifacts in the data located south of Fishing Point shoreline. This day logged substantial swell from the South, creating notable motion in the survey lines running North and South. The line segments in waters closer to the shore, depths 7.0 m and less, display the these sound velocity artifacts the most. Once 3101 was in depths 8.0 m and greater the sound velocity artifacts are negligible.Geographic location of sound velocity artifacts.file:///H:/Surveys/OPR-D302-TJ-15/H12856/Data/Separates/Descriptive_Report/DR%20Multimedia/Motion_artifacts_2.jpgClose up view of sound velocity artifacts. Vertical exaggeration set at 20. file:///H:/Surveys/OPR-D302-TJ-15/H12856/Data/Separates/Descriptive_Report/DR%20Multimedia/Motion_artifacts_1.jpgSubset view of sound velocity artifacts. Note the symmetrical curl on the outer edges indicating these errors.file:///H:/Surveys/OPR-D302-TJ-15/H12856/Data/Separates/Descriptive_Report/DR%20Multimedia/Motion_artifacts_3.jpg3101 and 3102 Vertical OffsetsSurvey vessels 3101, and 3102 collected positioning data via POSMV units with Fugro Marinestar Precise Point Positioning raw data inputs. All raw data was run through Post Processed Precise Point Positioning (5P) using POSPac MMV 7.1.5812.24143 software. Survey launches 3101 and 3102 exhibited high vertical offsets after the POSPac SBETs were applied. Data which exhibited vertical offset measurements greater than 30 cm were reprocessed using IAPPK solutions. The following survey days' positioning data for launch 3101 was reprocessed using an IAPPK solution; DN342, DN343, DN344 DN345, DN346, DN347, DN347. The following survey days' positioning data for launch 3102 was reprocessed using an IAPPK solution; DN342, DN343. In all, 95.9% of the multibeam data was processed using IAPPK and 4.1% was processed using Marinestar 5P.Vertical offsets of 3101 and 3102 over charted wreck using a 5P solution. Viewed by a Depth layer.file:///H:/Surveys/OPR-D302-TJ-15/H12856/Data/Separates/Descriptive_Report/DR%20Multimedia/Vertical_offset_5P.jpgSubset of vertical offsets of 3101 and 3102 over charted wreck using a 5P solution. Approximately 1.309 m difference.file:///H:/Surveys/OPR-D302-TJ-15/H12856/Data/Separates/Descriptive_Report/DR%20Multimedia/Vertical_offset_5P_2.jpgThe same wreck as in the previous images, with an IAPPK solution applied to 3101 and 3102. Viewed by a Depth layer.file:///H:/Surveys/OPR-D302-TJ-15/H12856/Data/Separates/Descriptive_Report/DR%20Multimedia/Vertical_offset_IAPPK_1.jpgSubset over same wreck as in previous images, with an IAPPK solution. 0.0 m vertical difference.file:///H:/Surveys/OPR-D302-TJ-15/H12856/Data/Separates/Descriptive_Report/DR%20Multimedia/Vertical_offset_IAPPK_2.jpgBase stations utilized by 3101's IAPPK solutions.file:///H:/Surveys/OPR-D302-TJ-15/H12856/Data/Separates/Descriptive_Report/DR%20Multimedia/3101_Days_IAPPK.jpgBase stations utilized by 3102's IAPPK solutions.file:///H:/Surveys/OPR-D302-TJ-15/H12856/Data/Separates/Descriptive_Report/DR%20Multimedia/3102_Days_IAPPK.jpgSound Speed Cast Frequency: CTD cast performed by launches 3101 & 3102 were taken at a minimum of 4 hour intervals; or in areas where surface sound speed changed by 3 m/s compared to the previous cast taken. These cast were also applied to the data collected by Z-1 and Z-2. Sound speed profiles were distributed based on safe deployment of equipment, depth and notable changes in surface sound speed. To account for differing water masses, casts were taken in both shallow and deep water relative to the areas being surveyed during the 4 hour time frame.H12856 geographic coverage of sound velocity casts from 3101,3102 and those applied to Z-1 and Z-2.file:///H:/Surveys/OPR-D302-TJ-15/H12856/Data/Separates/Descriptive_Report/DR%20Multimedia/SV_Profile_Coverage.jpgAll 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.Raw Backscatter was logged as a 7k file and has been sent to the Processing Branch. One line per vessel per day was processed by the field unit for quality assurance.CarisHIPS & SIPS9.0.20FledermausFMGT7.4.5NOAA Profile V_5_3_3H12856_MB_50cm_MLLW_Finalized.csarCUBE0.52.5811.38NOAA_0.5mObject DetectionH12856_MB_1m_MLLW_Finalized.csarCUBE11.2812.83NOAA_1mMBES TracklineSBES Set Line SpacingH12856_Combined_4m_MLLW_FinalizedCUBE4-0.1512.74NOAA_4m100% SSSH12856_VB_4m_MLLW_Finalized.csarCUBE4-0.159.54NOAA_4mMBES TracklineSBES Set Line SpacingH12856_SSS_100SSS Mosaic100N/A100% SSSPer section 5.2.2.1 of the NOAA HSSD Manual (ed 2015), all Object Detection MBES data was gridded according to depth: 0.5m resolution for depths ranging from 0 - 20m. Per section 5.2.2.2 of the NOAA HSSD Manual (ed 2015), MBES surfaces were gridded according to guidelines for Complete Coverage utilizing Side Scan Sonar coverage with concurrent single beam or multibeam. Surface H12856_Combined_4m_MLLW_Finalized was utilized to include all multi beam and vertical beam data. Surfaces H12856_VB_4m_MLLW_Finalized and H12856_Combined_4m_MLLW_Finalized exhibit a minimum value of -0.15m within their depth ranges. This is due to the respective Z-boat collecting the vertical beam data utilized actually logged data over exposed or awash shoreline. Area highlighted where vertical beam data exhibits negative depth values. Indicating exposed or awash land or shoreline.file:///H:/Surveys/OPR-D302-TJ-15/H12856/Data/Separates/Descriptive_Report/DR%20Multimedia/Negative_value.jpgAdditional information discussing the vertical or horizontal control for this survey can be found in the accompanying HVCR.Mean Lower Low WaterTCARIWachapreague 86310448631044.tidFinal ApprovedD302TJ2015_H12856.tcFinal2016-01-062016-01-18VDatumOPR-D302-TJ-15_ChincoteagueInlet_VDatum_SEP.csarAll soundings submitted as H12856 are reduced to MLLW using documented VDatum techniques. If it is deemed necessary to change the water level reduction method to discrete zoning the following additional information will be useful: 1) The National Water Level Observation Network (NWLON) stations serving as datum control for this survey is Wachapreague, VA (8631044). 2) The submitted water level files (8631044.tid) are the final approved water levels for the period of hydrography. These files have been loaded to all CARIS lines submitted as H12856. 3) The submitted tide corrector (D302TJ2015_H12856.tc) is the preliminary zoning file that was accepted as final per final tide note, submitted in Appendix I. This file has been loaded to all CARIS lines submitted as H12856.North American Datum of 1983 (NAD83)UTM zone 18Smart BaseN/AVAWIN/ACOVXN/ADED2N/AHNPTN/ALOYWN/ANJCMNOAA Ship Thomas Jefferson and her launches acquire positioning data via POSMV TPUs. The launches 3101 and 3102 utilize a POSMV 4. The POSMV 4 TPUs have an upgraded firmware package allowing them to collect data comparable to a POSMV 5. All of these TPUs utilize a Fugro Marinestar Virtual Base Station subscription which collects Precise Point Positioning data.Chart comparison procedures were followed as outlined in section 4.5 of the FPM (2014 ed) and section 8.1.4 sub section D.1 of the HSSD (2015 ed). The ENC and RNC versions of the relevant charts were reviewed to ensure that the latest USCG Local Notice to Mariners (LNM) has been applied. Additional chart comparisons for survey H12856 were conducted using selected sounding sets generated from H12856_MB_1m_MLLW_Finalized.csar and H12856_VB_4m_MLLW_Finalized.csar at chart scale (1:10000) with a radius of 1m. In CARIS BDB, the soundings were then converted into a point cloud, from which a 1m and a 4m interpolated surface were generated. Contouring was run on the interpolated surface and the results are shown in the figure below.Northern portion of H12856 contours overlaid on RNC 12210_1.file:///H:/Surveys/OPR-D302-TJ-15/H12856/Data/Separates/Descriptive_Report/DR%20Multimedia/H12856_Contours_RNC122101_1.jpgSouthern portion of H12856 contours overlaid on RNC 12210_1.file:///H:/Surveys/OPR-D302-TJ-15/H12856/Data/Separates/Descriptive_Report/DR%20Multimedia/H12856_Contours_RNC122101_2.jpgNorthern portion of H12856 contours overlaid on ENC US4VA70M.file:///H:/Surveys/OPR-D302-TJ-15/H12856/Data/Separates/Descriptive_Report/DR%20Multimedia/H12856_Contours_ENCUSFVA70M_1.jpgSouthern portion of H12856 contours overlaid on ENC US4VA70M.file:///H:/Surveys/OPR-D302-TJ-15/H12856/Data/Separates/Descriptive_Report/DR%20Multimedia/H12856_Contours_ENCUSFVA70M_2.jpg1221055020000402015-082015-11-282015-11-28There is much variation and change when comparing the current H12856 survey data to Chart 12210_2. The larger scale of Chart 12210_2 lends to a better comparison of current to historic survey data. In this comparison we see a good agreement between charted and surveyed contours. Depths do vary across a wide range of values. With such a wide range of differences, to quantify or visually describe would be superfluous. It is suggested to base new contours and depths off complete data collected by survey H12856 per or exceeding Project Instructions. Northern portion of Chincoteague Inlet. Contours derived from vertical and multibeam data are displayed.file:///H:/Surveys/OPR-D302-TJ-15/H12856/Data/Separates/Descriptive_Report/DR%20Multimedia/H12856_Contours_RNC12210_2_1.jpg1221055180000402015-082015-10-282015-11-28There is much variation and change when comparing the current H12856 survey data to Chart 12210_1. With such a wide range of differences, to quantify or visually describe would be superfluous. It is suggested to base new contours and depths off complete data collected by survey H12856 per or exceeding Project Instructions. Northern portion of Chincoteague Inlet. Contours derived from vertical and multibeam data are displayed.file:///H:/Surveys/OPR-D302-TJ-15/H12856/Data/Separates/Descriptive_Report/DR%20Multimedia/H12856_Contours_RNC12210_1_1.jpg1221155280000452013-052015-10-222015-11-28RNC 12211 coincides with raster chart 12210 Kapp 551. The comparison between survey H12856 and RNC 12211 is equivalent to the preceding comparison with RNC 12210. The Hydrographer recommends updating all contours and soundings with the digital data from survey H12856.US4VA70M8000012016-02-182016-02-26falseENC US4VA70M coincides with raster chart 12210 Kapp 551. The depths and contours on the ENC match the raster 12210. The comparison between survey H12856 and the ENC is equivalent to the preceding comparison with Chart 12210. The Hydrographer recommends updating all contours and soundings with the digital data from survey H12856.No Maritime Boundary Points were assigned for this survey. See the H12856_FFF.hob final feature file for this survey. See the H12856_FFF.hob final feature file for this survey.1Danger to Navigation Reports are included in Appendix II of this report.Danger to Navigation Reports are included in Appendix II of this report. Channels were investigated in conjunction with the chart comparison. Generally the contours and depths of the channels were in agreement especially in the northeastern portion of the inlet. Channel depths in the southwestern portion of the sheet had the greatest differences when compared to charted soundings. Refer to the chart comparisons in section D.1. The Hydrographer recommends updating all contours and soundings with the digital data from survey H12856.Overview of channel area with greatest difference in surveyed and charted depths.file:///H:/Surveys/OPR-D302-TJ-15/H12856/Data/Separates/Descriptive_Report/DR%20Multimedia/Channel_comp_1.jpgDepths in channel range from 26' -31' in a charted 33' area. east of Gunboat Point.file:///H:/Surveys/OPR-D302-TJ-15/H12856/Data/Separates/Descriptive_Report/DR%20Multimedia/Channel_comp_2.jpgA total of 7 bottom samples were taken for survey H12856. These were taken in places in possible anchorage sites, as well as those based on the assigned bottom sample sites provided in the Project Reference File for survey H12856. Many of the sites within the PRF were outside of collected survey data and were shifted to sites with the survey data based on the discretion of the field unit and Chief Hydrographer.Bottom samples are displayed as point features represented with a SBDARE symbol.file:///H:/Surveys/OPR-D302-TJ-15/H12856/Data/Separates/Descriptive_Report/DR%20Multimedia/Bottom_samples_sites.jpgShoreline was not assigned in the Hydrographic Survey Project Instructions or Statement of Work.Prior surveys were reviewed by the field unit to provided an insight to the dynamics of the environment for survey H12856. Based on field observations, ATONs are properly placed and charted.Overhead features exist for this survey, but were not investigated.No submarine features exist for this survey.No ferry routes or terminals exist for this survey.No platforms exist for this survey.Refer to H12856_FFF.hob final feature, as well as the DTON report for survey H12856. No present or planned construction or dredging exist within the survey limits.Due to time constraints and necessary equipment, it is highly recommended to further investigate and survey Chincoteague Inlet and its surrounding waters.It is recommend to provide an inset at a higher resolution that overlaps RNC 12210_2. Recommended inset area for Chincoteague inlet and RNC 12210.file:///H:/Surveys/OPR-D302-TJ-15/H12856/Data/Separates/Descriptive_Report/DR%20Multimedia/inset.jpgAs 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.Shepard M. Smith, CAPT/NOAAChief of Party2016-03-21Joseph K. Carrier III, LT/NOAAField Operations Officer2016-03-21Alex C. LigonSheet Manager2016-03-21