OPR-D302-KR-13Coastal VirginiaCoastal VirginiaLeidos (formerly SAIC)H12560213 NM East of Sand Shoal InletVirginiaUnited States400002013Charles F. HollowayBasic Hydrographic Survey2012-04-062013-08-062013-10-04Multibeam Echo SounderSide Scan SonarMultibeam Echo Sounder BackscattermetersUniversal Transverse Mercator (UTM)UTCAtlantic Hydrographic BranchContract: DG133C-08-CQ-0003 Contractor: Leidos 221 Third Street, Newport, RI 02840 USA. Subcontractors: Divemasters, Inc., 15 Pumpshire Road, Toms River, NJ 08753; Rotator Staffing Services, 25 Kennedy Blvd., East Brunswick NJ 08816. Leidos Doc 14-TR-018. ContractorThe area surveyed was a section of Coastal Virginia 13 NM East of Sand Shoal Inlet (Figure 1). 37.346730555675.606633333337.247675.43196111111H12560 Survey Boundsfile:///M:/charlie/NOAA_DELMARVA_2013/H12560/DR_Working/H12560_Figure_1.jpgThe purpose of this project is to provide contemporary surveys to update National Ocean Service (NOS) nautical charting products. This project will cover approximately 109 square nautical miles, of which approximately 87 square nautical miles are designated critical survey area, as designated in the NOAA Hydrographic Survey Priorities (NHSP), 2012 Edition.The entire survey is adequate to supersede previous data.Leidos, formerly Science Applications International Corporation (SAIC), warrants only that the survey data acquired by Leidos and delivered to NOAA under Contract DG133C-08-CQ-0003 reflects the state of the sea floor in existence on the day and at the time the survey was conducted. H12560 was surveyed in accordance with the following documents: 1. Project Instructions, OPR-D302-KR-13, dated 06 April 2012 2. Statement of Work, Hydrographic Survey Services, dated 11 April 2013 3. NOS Hydrographic Specifications and Deliverables, April 2013, released 18 April 2013 (HSSD) Survey Limits were acquired in accordance with the requirements in the Project Instructions and the HSSD.2Final Bathymetry Coverage for H12560file:///M:/charlie/NOAA_DELMARVA_2013/H12560/DR_Working/H12560_Figure_2.jpgSurvey Coverage was in accordance with the requirements in the Project Instructions and the HSSD.2013-08-062013-08-072013-08-082013-08-092013-08-102013-08-112013-08-122013-08-132013-08-142013-08-152013-08-162013-08-172013-08-202013-08-212013-08-222013-10-012013-10-040100035.75M/V Atlantic Surveyor000001026.3085.10000001026.3085.108.3Leidos used their ISS-2000 software on a Windows XP platform to acquire these survey data. Survey planning and data analysis were conducted using the Leidos SABER software on Red Hat Enterprise 5 Linux platforms. L-3 Klein 3000 side scan data were collected on a Windows XP platform using L-3 Klein’s SonarPro software. Subsequent processing and review of the side scan 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-D302-KR-13, previously delivered with the H12559 Descriptive Report (DR) on 16 May, 2014. There were no variations from the equipment configuration described in the DAPR. M/V Atlantic Surveyor1109The M/V Atlantic Surveyor was used to collect multibeam sonar (RESON 7125 SV), side scan sonar (L-3 Klein 3000), and sound speed data during twenty-four hours per day survey operations. A detailed description of the vessel used is included in Section A of the Data Acquisition and Processing Report (DAPR).Teledyne RESONSeabat 7125 SVMBESL-3 Klein3000SSSApplanixPOS/MV 320Positioning and Attitude SystemTrimbleProbeaconPositioning SystemRolls Royce MVP-30Sound Speed SystemA detailed description of the equipment installed on each vessel is included in Section A of the Data Acquisition and Processing Report (DAPR).There were 85.1 linear nautical miles of crosslines and 1026.3 linear nautical miles of main scheme lines surveyed on H12560. This resulted in crossline mileage approximately 8.3% of the main scheme mileage which meets the requirement (Section 5.2.4.3 of the HSSD) to achieve at least eight percent for a multibeam survey using set line spacing. The main scheme lines were orientated 22°/202° and spaced 65 meters apart. Crosslines were oriented 90°/270° and spaced 800 meters apart. Refer to the “Multibeam Processing Log” section within Separates I for information on the delineation of main scheme and crossline data files. In the field, hydrographers conducted daily comparisons of main scheme to near nadir crossline data to ensure that no systematic errors were introduced and to identify potential problems with the survey system. After the application of all correctors and completion of final processing in the office, separate two-meter CUBE PFM grids were built. One grid contained the full valid swath (±60° from nadir) of main scheme multibeam data and the other included only the near nadir swath (±5° from nadir) crossline data. A difference grid was then generated by subtracting the CUBE depths in the main scheme PFM from the CUBE depths in the crossline PFM. The SABER Frequency Distribution Tool was used to analyze the difference grid. Comparisons of all final crossing data in H12560 showed that 98.61% were within 25 centimeters. These comparisons fall within the requirement defined in Section 5.2.4.3 of the HSSD, which states that at least 95% of the depth difference values are to be within the maximum allowable total vertical uncertainty (calculated to be between 0.520 and 0.612 meters for the water depths observed in H12560). See Separates II for a complete discussion of the analysis and tabular results. The Total Propagated Uncertainty (TPU) model that Leidos has adopted had its genesis at the Naval Oceanographic Office (NAVOCEANO), and is based on the work by Rob Hare and others (“Error Budget Analysis for NAVOCEANO Hydrographic Survey Systems, Task 2 FY 01”, 2001, HSRC FY01 Task 2 Final Report). Once the TPU model is applied to the GSF bathymetry data, each beam is attributed with the horizontal uncertainty and the vertical uncertainty at the 95% confidence level. For specific details on the use and application of the SABER Total Propagated Uncertainty model, see Section B.1 in the DAPR. The vertical and horizontal uncertainty values that were estimated by the TPU model for individual multibeam soundings varied little across the dataset, tending to be most affected by beam angle in the multibeam data. During application of horizontal and vertical uncertainties to the GSF files, individual beams where either the horizontal or vertical uncertainty exceeded the maximum allowable IHO S-44 5th edition Order 1a specifications were flagged as invalid. As a result, all individual soundings used in development of the final CUBE depth surface had modeled vertical and horizontal uncertainty values at or below the allowable IHO S-44 5th edition, Order 1a uncertainty. During the creation of the CUBE surface, two separate vertical uncertainty surfaces are calculated by the SABER software. One surface contains the standard deviation of all soundings that are contributing to the CUBE hypothesis (Hyp. StdDev) and the other contains the average of the vertical uncertainty of all soundings contributing to the CUBE hypothesis (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). For specific details on this process see Section B.2 of the DAPR. The final two-meter PFM CUBE surface contained final vertical uncertainties that ranged from 0.270 to 0.659 meters. The IHO Order 1a maximum allowable vertical uncertainty was calculated to range between 0.520 to 0.612 meters, based on the minimum CUBE depth (11.044 meters) and maximum CUBE depth (27.204 meters). The SABER Check PFM Uncertainty function was used to highlight all instances in the Hyp. Final Uncertainty surface where a given node exceeded the IHO Order 1a allowable vertical uncertainty for the CUBE depth at that node. The final two-meter PFM CUBE surface contained one CUBE node with a final vertical uncertainty that exceeded IHO Order 1a allowable vertical uncertainty. This high vertical uncertainty resulted from a small depth difference in the outer beams of adjacent swaths. The SABER Check PFM Uncertainty function was also run on each of the two half-meter feature PFM Hyp. Final Uncertainty surfaces. The results are listed in Figure 3. As expected, there are higher numbers of nodes that exceed uncertainty limits due to the smaller node resolution and the high variability of sounding depths around features. The SABER Frequency Distribution Tool was also used to review the Hyp. Final Uncertainty surface within the two-meter grid and two half-meter resolution PFM grids. The results show that in the two-meter PFM, 99.75% of all nodes had final uncertainties less than or equal to 0.300 meters. In the two individual feature PFM grids, at least 99.78% of all grid nodes contained total vertical uncertainties of 0.300 meters or less. 3Number of Nodes Exceeding the Allowable IHO Order1a Uncertainty in the Feature BAG Files 1 of 2 and 2 of 2file:///M:/charlie/NOAA_DELMARVA_2013/H12560/DR_Working/H12560_Figure_3.jpgAn analysis of H12560 junctions with contemporary surveys H12396, H12397, and H12559 was performed. Note that the Project Instructions stated that junctions should be performed on H12395 as well, however, there were no overlapping data from H12560 and this survey. Figure 4 shows the general locality of H12560 as it relates to the sheets for which junctions were performed. Details for H12396, H12397, and H12559 are listed in Table 6. See Separates II for a complete discussion of the junction results and tabular listings. Analysis of the junction with H12561 was not conducted, as the processing efforts for this sheet were still ongoing.4General Locality of H12560 with Contemporary Surveysfile:///M:/charlie/NOAA_DELMARVA_2013/H12560/DR_Working/H12560_Figure_4.jpgH12396400002012Leidos (formerly SAIC)NWH12560 junctions with H12396 to the Northwest. 94.33% of the soundings differ by ±0.55 meters.H12397400002012Leidos (formerly SAIC)NEH12560 junctions with H12397 to the Northeast. 96.58% of the soundings differ by ±0.40 meters.H12559200002013Leidos (formerly SAIC)WH12560 junctions with H12559 to the West. 99.35% of the soundings differ by ±0.30 meters.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.On the M/V Atlantic Surveyor, the MVP-30 was used to collect sound speed profile (SSP) data. 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. There were times when the sound speed values exceeded the two meters/second threshold due to the local temporal and tidal variability. During these times, several profiles were acquired and reapplied in an effort to reduce these effects. The product of this effort resulted in the final data bearing no significant artifacts due to sound speed differences.Additional information can be found in Section A.8 of the DAPR. A total of 459 sound speed profiles were applied to online data for H12560. All profiles that were applied for online bathymetry data collection were acquired within the bounds of the survey area. Please refer to the DAPR for specific details regarding acquisition (Section A.8) and application (Section C.1.3) of sound speed profiles. Confidence checks of the sound speed profile casts were conducted periodically (approximately once per week) by comparing at least two consecutive casts taken with different SV and P Smart Sensors. Six sound speed confidence checks were conducted during H12560 and the results can be found in Separates II within the “Comparison Cast Log” section. Sound speed profiles were obtained for four different survey purposes. The “Sound Speed Profile Log” section of Separates II is a cumulative report detailing each cast associated with H12560. The log is separated by the purpose of the applied cast; with individual tables for “Used for MB” (online bathymetry), “Used for Comparison”, “Used for Lead Line”, and “Used for Closing”. Additionally, in a separate folder on the delivery drive (H12560/Data/Processed/SVP/CARIS_SSP), there are four CARIS SSP files (.svp). These files contain concatenated SSP data that have been formatted for use in CARIS. The CARIS SSP files are designated based on the purpose of the cast and their filenames match the tables within the "Sound Speed Profile Log". All sound speed profile files are delivered with the H12560 delivery data and are broken out into sub-folders, which correspond to the purpose of each cast.All equipment and survey methods were used as detailed in the DAPR.Coverage AnalysisThe Project Instructions specified coverage requirements in the survey area as “(1) 200% Side Scan Sonar (SSS) with concurrent Set Line Spacing, Multibeam (MBES) and Backscatter, or (2) 200% SSS with concurrent Vertical Beam Echosounder (VBES), or (3) Object Detection MBES with Backscatter”. Leidos choose to meet the coverage requirements with 200% side scan with concurrent set line spacing multibeam. To achieve this coverage the M/V Atlantic Surveyor used a towed L-3 Klein 3000 side scan sonar set to a 75-meter range and a main scheme line spacing of 65 meters. This survey scenario provided a consistent 150-meter side scan imagery swath and up to 20 meters of side scan overlap between adjacent lines within each 100% coverage and resulting multibeam coverage. The SABER Gapchecker routine was used to flag bathymetry data gaps exceeding the allowable limit of three contiguous nodes. 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. A final review of the CUBE Depth surface in the two-meter grid showed that valid depths exist in 100% of the nodes and there were no areas where three or more nodes sharing adjacent sides lacked data. All 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 of the PFM grid. The Hyp # Soundings surface reports the number of soundings that were used to compute the chosen hypothesis. Analysis of the H12560 two-meter PFM grid revealed that 99.74% of all nodes contained three or more soundings; satisfying the requirements for set line spacing surveys, as specified in Section 5.2.2.3 of the HSSD. Analysis of the two half-meter PFM grids showed a minimum of 95.74% of all individual nodes contained five or more soundings to meet object detection coverage (HSSD Section 5.2.2.1).All data reduction procedures conform to those detailed in the DAPR.All sounding systems were calibrated as detailed in the DAPR.In accordance with the April 2013 NOS HSSD and the Project Instructions, Leidos collected multibeam backscatter with all GSF data acquired by the RESON 7125 SV. The multibeam settings were checked to ensure acceptable quality standards were met and to avoid any acoustic saturation of the backscatter data. The multibeam backscatter data acquired by each system were written to the GSF in real-time by ISS-2000 and are delivered in the final GSF files for each sheet. NOAA Extended Attribute Files V5-2.H12560_MB_2m_MLLWBAG211.04427.204N/AMBES TracklineSBES Set Line SpacingH12560_MB_50cm_MLLW_1of2BAG5021.07023.177N/AObject DetectionH12560_MB_50cm_MLLW_2of2BAG5020.16821.626N/AObject DetectionH12560_ss_1_100SSS Mosaic1N/A100% SSSH12560_ss_2_100SSS Mosaic1N/A100% SSSA PFM CUBE Depth surface was used to assess and document multibeam survey coverage. The CUBE depth is populated 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 in H12560 was from 11.044 meters, 0.270-meter uncertainty (36 feet) to 27.204 meters, 0.288-meter uncertainty (89 feet). Section 5.2.2.3 of the HSSD requires a four-meter grid resolution for depths ranging from zero meters to 40 meters for set line spacing surveys. Due to the range of depths encountered on this project, Leidos requested and was granted permission to deliver all final grids at the higher two-meter node resolution. Therefore, final CUBE surfaces for H12560 were generated at two-meter grid node resolution. Over significant features, CUBE surfaces were generated at half-meter grid node resolution to meet the object detection specifications defined in Section 5.2.2.1 of the HSSD. Two significant features were identified in H12560 and two half-meter resolution PFM grids were generated to cover these features. Data within the half-meter resolution CUBE PFM grids also remain in the two-meter CUBE PFM grid. The final gridded bathymetry data are delivered as Bathymetric Attributed Grids (BAG). The BAG files were exported from CUBE PFM grids as detailed in Section B.2.4 of the DAPR. As of the date of delivery of H12560, CARIS does not support version 1.5.1 BAGs with optional surfaces. Therefore, BAG version 1.1.0 files are delivered. Since the BAG version 1.1.0 files only contain two surfaces, the standard CUBE Depth and Final Hyp. Uncertainty, BAGs will be delivered with the additional surfaces delivered as supplemental non-standard BAG files. These additional BAG files were generated through the same process as the standard BAG files. The version 1.1.0 BAG format only allows for a Depth surface and an Uncertainty surface. Therefore, each of the non-standard BAG files were created with the CUBE Depth values populating the Depth surface of the BAG and each of the additional group surfaces listed below populating the Uncertainty surface of the BAG. Please note when reviewing these additional, non-standard version 1.1.0 BAG files the file name designates the layer that populates the Uncertainty layer of the BAG (Figure 5). Please also note that when displayed the two layers of the BAG remain named Depth and Uncertainty. These non-standard BAGs are provided for review purposes only and are not intended to be used as archival products. These additional surfaces are referred to as Elevation Solution Group surfaces and Node Group surfaces. Note that by definition, BAG files contain elevations not depths however; many software packages display a BAG elevation surface as a depth (positive values indicating water depth). The Elevation Solution Group is made up of the following three surfaces: · shoal elevation - the elevation value of the least-depth measurement selected from the sub-set of measurements that contributed to the elevation solution. · number of soundings - the number of elevation measurements selected from the sub-set of measurements that contributed to the elevation solution. · stddev - the standard deviation computed from all elevation values which contributed to any hypothesis within the node. Note that the stddev value is computed from all measurements contributing to the node, whereas shoal elevation and number of soundings relate only to the chosen elevation solution. The Node Group is made up of the following two surfaces: · hypothesis strength - the CUBE computed strength of the chosen hypothesis. · number of hypotheses - the CUBE computed number of hypotheses. 5Summary of Non-standard H12560 BAG Filesfile:///M:/charlie/NOAA_DELMARVA_2013/H12560/DR_Working/H12560_Figure_5.jpgSide Scan Coverage AnalysisFor all details regarding side scan data processing, see Section B.3 of the DAPR. The Project Instructions required (1) 200% Side Scan Sonar (SSS) with concurrent Set Line Spacing Multibeam (MBES) and Backscatter, or (2) 200% SSS with concurrent Vertical Beam Echosounder (VBES), or (3) Object Detection MBES with Backscatter. Leidos chose to meet the coverage requirements with 200% side scan with concurrent set line spacing multibeam. The 200% side scan coverage was verified by generating two separate 100% coverage mosaics at one-meter cell size resolution as specified in Section 8.3.1 of the HSSD. The first and second 100% coverage mosaics were independently reviewed using tools in SABER to verify data quality and swath coverage. Both coverage mosaics are determined to be complete and sufficient to meet the requirements contained within the Project Instructions. The mosaics are delivered as TIFF (.tif) images with accompanying world files (.tfw). · H12560_ss_1_100_mosaic · H12560_ss_2_100_mosaic Side scan sonar contacts were investigated and confirmed using SABER Contact Review. All side scan sonar contacts and accompanying images are delivered in the Side Scan Sonar Contacts S-57 file. No vertical or horizontal controls were established, recovered, or occupied during data acquisition for OPR-D302-KR-13, which includes H12560. Therefore a Horizontal and Vertical Control Report was not required. Mean Lower Low WaterDiscrete ZoningDuck, NC86513708651370_verified_07102013_10062013.tidVerified ObservedD302KR2013CORP.zdfFinalNo final tide note was provided by the NOAA Center for Operational Oceanographic Products and Services (CO-OPS). Leidos is not required to have a final tide note from CO-OPS for H12560 however, a final tide note has been provided by Leidos in Appendix I. The Project Instructions specified NOAA tide station 8651370 Duck, NC as the source for water level correctors. A full explanation of the tide zone assessment is detailed in Section C.4 of the DAPR. For H12560, 8651370 Duck, NC was the source of all final verified water level heights for determining correctors to soundings. All data for H12560 were contained within two tide zones (SA54 and SA55) which were provided from NOAA. Leidos did not revise the delivered tide zones for tide station 8651370 Duck, NC as the water level zoning parameters in the file D302KR2013CORP.zdf, provided by National Ocean Service (NOS) were deemed adequate for the application of observed verified water levels. As a result, they were accepted as final and applied to all H12560 bathymetry data. North American Datum of 1983 (NAD83)UTM Zone 18, NorthDriver, VA (289 kHz)Annapolis, MD (301 kHz)New Bern, NC (294 kHz)Please refer to the DAPR for details regarding all antenna and transducer offsets. Horizontal positioning of the multibeam transducer by the POS/MV was verified by frequent comparison checks against an independent DGPS system. During survey data acquisition, the ISS-2000 real-time system provided a continuous view of the positioning comparison between the POS/MV and the Trimble DGPS. An alarm was triggered within ISS-2000 if the comparisons were not within an acceptable range. Any soundings with total horizontal uncertainties exceeding the maximum allowable IHO S-44 5th edition Order 1a specifications were flagged as invalid and therefore not used in the CUBE Depth calculations. Daily positioning confidence checks for H12560 were conducted several times throughout the day and a daily value is presented as a table within Separates I, “Daily Positioning Confidence Checks”. Daily positioning confidence checks for the M/V Atlantic Surveyor were within 0.61 meters. The chart comparisons were conducted using the Leidos SABER software to view the BSB raster charts with overlain data for H12560 such as the CUBE gridded surface, selected soundings, contacts, and features. Charting recommendations for depths follow Section 5.1.2 of the HSSD where depths and uncertainties are to be rounded by standard arithmetic rounding (round half up) and accompanying chart depth units are rounded using NOAA cartographic rounding (0.75 round up). All CUBE depths and uncertainty values are provided to millimeter precision. For ENC comparisons, a combination of Jeppesen’s dKart Inspector, SevenCs’ SeeMyDENC, and CARIS’ EasyView were used in conjunction with SABER. United States Coast Guard (USCG) District 5 Local Notice to Mariners publications were reviewed for changes subsequent to the date of the Hydrographic Survey Project Instructions and before the end of survey (as specified in Section 8.1.4 of the HSSD). The Notice to Mariners reviewed were from week 27/13 (02 July 2013) until week 41/13 (08 October 2013).122215588000082014-022014-04-292014-04-26Chart 12221 covers the survey area west of 075° 29’ 00.00”W. There are no federally maintained channels within H12560 on this chart. The charted 60-foot depth curves were generally found to be in agreement with the H12560 survey data. CUBE depths within sheet H12560 were generally within ±3 feet of the charted depths. There were no charted soundings or features not specifically assigned as an AWOIS item within H12560 on this chart. The AWOIS item on this chart is discussed in Section D.1.3. All new uncharted features found, assigned AWOIS items, and charted feature updates are documented in the Final Feature File (S-57). 12200526419706502011-072014-04-292014-04-26Chart 12200 covers the entire survey area. There are no federally maintained channels within H12560 on this chart. The charted 10-fathom depth curves were generally found to be in agreement with the H12560 survey data. CUBE depths within sheet H12560 were generally within ±1 fathom of the charted depths. There were no charted soundings or features not specifically assigned as an AWOIS item within H12560 on this chart. The AWOIS item on this chart is discussed in Section D.1.3. All new uncharted features found, assigned AWOIS items, and charted feature updates are documented in the Final Feature File (S-57). US5VA12M80000222012-04-062014-02-26falseChart US5VA12M covers the survey area west of 075° 29’ 00.00”W. There are no federally maintained channels within H12560 on this chart. The charted 18.2-meter depth curve is generally in agreement with the H12560 survey data. CUBE depths within sheet H12560 were generally within ±1 meter of the charted depths. There were no charted soundings or features not specifically assigned as an AWOIS item within H12560 on this chart. The AWOIS item on this chart is discussed in Section D.1.3. All new uncharted features found, assigned AWOIS items, and charted feature updates are documented in the Final Feature File (S-57). US3DE01M419706142013-04-242014-04-28falseChart US3DE01M covers the entire survey area. There are no federally maintained channels within H12560 on this chart. The charted 18.2-meter depth curve is generally in agreement with the H12560 survey data. CUBE depths within sheet H12560 were generally within ±1 meter of the charted depths. There were no charted soundings or features not specifically assigned as an AWOIS item within H12560 on this chart. The AWOIS item on this chart is discussed in Section D.1.3. All new uncharted features found, assigned AWOIS items, and charted feature updates are documented in the Final Feature File (S-57). All assigned and information AWOIS item updates are included in the Final Feature File (S-57). AWOIS 959 was not found. The 500-meter search radius was investigated with 200% side scan and resulting multibeam coverage. No features and two non-significant contacts were found inside the search area. Leidos determined the contacts were not AWOIS 959.No Maritime Boundary Points were assigned for this survey.No charted features exist for this survey.See the S-57 Final Feature File for all the details and recommendations regarding new uncharted features investigated. No Danger to Navigation Reports were submitted for this survey.No shoals or potentially hazardous features exist for this survey.No channels exist for this survey. There are no designated anchorages, precautionary areas, safety fairways, traffic separation schemes, pilot boarding areas, or channel and range lines within the survey limits.No bottom samples were required for this survey.Shoreline was not assigned in the Hydrographic Survey Project Instructions or Statement of Work.Junction analysis with prior contemporary surveys H12396 (2012), H12397 (2012), and H12559 (2013) were conducted and the results are presented in Section B.2.3 of this Report.Within H12560 there was one USCG maintained Aid to Navigation (ATON), Hog Island Lighted Buoy 12. This ATON is not included in the S-57 Final Feature file as called for in the HSSD. The Feature Correlator Sheet for the ATON is presented as a JPEG file in the Multimedia folder, named by the feature number (H12560_Feature_004). ATON Hog Island Lighted Buoy 12 (Fl R 2.5s) was compared to the United States Coast Guard Light List Volume II Atlantic Coast, updated through LNM week 19/14. It was found to be serving its intended purpose.No overhead features exist for this survey.No submarine features exist for this survey.No ferry routes or terminals exist for this survey.No platforms exist for this survey.No significant features exist for this survey.No present or planned construction or dredging exist within the survey limits.Designated SoundingsNo designated soundings were set for H12560.Final Feature S-57 FileIncluded with the H12560 delivery is the S-57 Final Feature File, H12560_FFF.000. Details on how this file was generated and quality controlled can be found in Section B.2.6 of the DAPR. The S-57 feature file delivered for H12560 contains millimeter precision for the value of sounding (VALSOU) attribute. As specified in Section 8.2 of the HSSD, the S-57 feature file is in the WGS84 datum and is unprojected with all depth units in meters. All of the features found in H12560 are retained within the S-57 Final Feature File. Feature Correlator Sheets were exported as image files (.jpg) and are included in the S-57 Final Feature File under the NOAA Extended Attribute field “images” where applicable.Side Scan Sonar Contacts S-57 FileIncluded with the H12560 delivery is the Side Scan Sonar Contact S-57 File, H12560_SSCon.000. Details on how this file was generated and quality controlled can be found in Section B.2.6 of the DAPR. As specified in Section 8.2 of the HSSD, the S-57 feature file is in the WGS84 datum and is unprojected with all depth units in meters.No new surveys or further investigations are recommended for this area.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.Charles F. HollowayLead Hydrographer2014-05-23Descriptive Report, H125592014-05-16Data Acquisition and Processing Report2014-05-16