OPR-K371-KR-19Port Arthur Traffic LanesPort Arthur, TXSAICH13217513 NM ESE of Galveston Bay EntranceTexasUnited States400002019Paul L. DonaldsonNavigable Area2019-02-212019-07-302019-09-20Multibeam Echo SounderSide Scan SonarMultibeam Echo Sounder BackscattermetersUTCAtlantic Hydrographic BranchContract: EA-133C-14-CQ-0033/TO-0005. Contractor: Leidos, 221 Third Street, Newport, RI 02840 USA. Subcontractors: Divemasters, Inc., 15 Pumpshire Road, Toms River, NJ 08753; OARS, 8705 Shoal Creek Blvd, Suite 109, Austin, TX 78757. Leidos Doc. 20-TR-002. All times were recorded in UTC. Data were collected in North American Datum of 1983 (NAD83) 2011 realization 2010 (NAD83(2011)2010.0), UTM Zone 15N.Any revisions to the Descriptive Report (DR) applied during office processing are shown in red italic text. The DR is maintained as a field unit product, therefore all information and recommendations within this report are considered preliminary unless otherwise noted. The final disposition of survey data is represented in the NOAA nautical chart products. All pertinent records for this survey are archived at the National Centers for Environmental Information (NCEI) and can be retrieved via https://www.ncei.noaa.gov/. Products created during office processing were generated in NAD83 UTM 15N, MLLW. All references to other horizontal or vertical datums in this report are applicable to the processed hydrographic data provided by the field unit. Office Revision: Field Work Start Date was changed from 7/30/2019 to 7/26/2019 to conform with the dates in DR Section A.5.ContractorThe area surveyed was a section of the Gulf of Mexico ESE of Galveston Bay Entrance, Texas (Figure 1).29.44448794.60791529.2565894.367578H13217 Survey BoundsSupportFiles\H13217_Figure_01.jpgSurvey limits were acquired in accordance with the requirements in the Project Instructions and the Hydrographic Surveys Specifications and Deliverables (HSSD) March 2019.The purpose of this survey is to provide contemporary surveys to update National Ocean Service (NOS) nautical charting products. Port Arthur, located on the Gulf of Mexico Intra-costal Waterway in Texas, is home to a large refinery network (1). The Port of Port Arthur hosts the Motiva refinery, the largest oil refinery in the United States (2). Traffic flow through the Port is heavy and in 2010, an oil spill occurred from an oil tanker and barge collision spilling 450,000 gallons of oil into the Sabine/Neches waterway (3). This busy seaport has also been hit by several hurricanes. On August 29, 2017, Hurricane Harvey hit Port Arthur bringing upwards of 40 inches of rainfall and widespread flooding to the area (4). This Hurricane had the potential to change the seafloor of the Port which sees over 35 million tons of vessel traffic (5). To continue to promote safe passage of traffic through the Port, this project will survey 286 square nautical miles (SNM) of seafloor in Port Arthur. The survey will address concerns of migrating shoals and exposed hazards by updating bathymetry and positions of hazards and reducing the risk to navigation. Survey data from this project is intended to supersede all prior survey data in the common area and will provide contemporary data to update National Ocean Service (NOS) nautical charting products. Citations 1. https://www.portarthurtx.gov/236/About-Us 2."Tropical Storm Harvey Closes America's Biggest Refinery". Maritime Executive. 30 August 2017. Retrieved 31 August 2017. 3. Gonzalez, Angel (24 January 2010). "Oil Spill Hits Texas Port". The Wall Street Journal. Retrieved 24 January 2010. 4. Harrington, Rebecca. "Flash floods send Texans into 'survival mode' as Harvey hits Port Arthur with 26 inches of rain in one day". BusinessInsider.com. Business Insider. Retrieved 30 August 2017. 5. The U.S. Waterway System, 2016 Transportation Facts & Information. Navigation and Civil Works Decision Support Center, U.S. Army Corps of Engineers.The entire survey is adequate to supersede previous data.Leidos warrants only that the survey data acquired by Leidos and delivered to NOAA under Contract EA-133C-14-CQ-0033 reflects the state of the sea floor in existence on the day and at the time the survey was conducted. H13217 was surveyed in accordance with the following documents: 1. Project Instructions, OPR-K371-KR-19, dated 21 February 2019 2. Hydrographic Surveys Specifications and Deliverables (HSSD), March 2019 3. Waiver_2019 HSSD_signed.pdf, dated 05 November 2019 4. OPR-K371-KR-19 Statement of Work, dated 21 February 2019All waters in survey areaComplete Coverage (Refer to HSSD Section 5.2.2.3). Complete 6443 LNMs. Transit mileage and data which do not meet HSSD specifications shall not count towards the completion of the LNM. Notify the Project Manager/COR upon nearing completion. The final survey area shall be squared off and ensure the full investigation of any features within the surveyed extent. Project Manager/COR may adjust survey prioritization based on observed shoaling. Additional or fewer sheets may be assigned based on survey area achieved.Leidos chose to achieve the coverage requirement using Complete Coverage, Option B (100% side scan sonar coverage with concurrent multibeam). Survey coverage achieved was in accordance with the requirements in the Project Instructions and the HSSD (Figure 2 through Figure 4).Final Bathymetry Coverage for H13217SupportFiles\H13217_Figure_02.jpgFinal Side Scan Coverage for H13217 (100% coverage)SupportFiles\H13217_Figure_03.jpgFinal Side Scan Coverage for H13217 (disproval coverage)SupportFiles\H13217_Figure_04.jpgM/V Atlantic Surveyor00000660.87031.80000000660.87031.8004.814000382019-07-262019-07-302019-07-312019-08-012019-08-032019-08-042019-08-052019-08-062019-08-102019-08-112019-08-122019-08-132019-09-142019-09-152019-09-20Leidos used their ISS-2000 software on a Windows 7 platform to acquire these survey data. Survey planning and data analysis were conducted using the Leidos SABER software on Red Hat Enterprise 7 Linux platforms. Klein 3000 side scan sonar (SSS) data were collected on a Windows 7 platform using Klein’s SonarPro software. Subsequent processing and review of the SSS data, including the generation of coverage mosaics, were accomplished using SABER. A detailed description of the systems and vessel used to acquire and process these data is included in the Data Acquisition and Processing Report (DAPR) for OPR-K371-KR-19, delivered previously with H13213. There were no variations from the equipment configuration described in the DAPR.M/V Atlantic Surveyor1109M/V Atlantic SurveyorSupportFiles\H13215_Figure_05.jpgThe M/V Atlantic Surveyor (Figure 5) was used to collect multibeam echo sounder (MBES) (RESON SeaBat T50), side scan sonar (SSS) (Klein 3000), and sound speed data during twenty-four hours per day survey operations. A detailed description of the vessel used is included in the DAPR.Teledyne RESONSeaBat T50-RMBESKlein Marine SystemsSystem 3000SSSApplanixPOS MV 320 v5Positioning and Attitude SystemAML OceanographicMVP30Sound Speed SystemA detailed description of the equipment installed is included in the DAPR.Refer to Separates II for details about how the crossing analyses were performed and a complete discussion of each analysis and tabular results. Figure 6 summarizes the crossline comparison results.Summary of Crossing AnalysisSupportFiles\H13217_Figure_06.jpgERS via VDATUM0.122M/V Atlantic SurveyorN/A1.0N/A1.0For specific details on the use and application of the SABER Total Propagated Uncertainty (TPU) model, refer to the DAPR. Once the TPU model was applied to the GSF bathymetry data, each beam was attributed with the horizontal uncertainty and the vertical uncertainty at the 95% confidence level. The vertical and horizontal uncertainty values, estimated by the TPU model for individual multibeam soundings, varied little across the dataset, tending to be most affected by beam angle. Individual soundings that had vertical and horizontal uncertainty values above IHO S-44 5th Edition, Order 1a were flagged as invalid during the uncertainty attribution. As discussed in the DAPR, SABER generates two vertical uncertainty surfaces; the Hypothesis Standard Deviation (Hyp. StdDev) and the Hypothesis Average Total Propagated Uncertainty (Hyp. AvgTPU). A third vertical uncertainty surface is generated from the larger value of these two uncertainties at each node and is referred to as the Hypothesis Final Uncertainty (Hyp. Final Uncertainty). The final H13217 one-meter PFM CUBE surface contained final vertical uncertainties that ranged from 0.260 meters to 0.526 meters. The IHO Order 1a maximum allowable vertical uncertainty was calculated to range between 0.516 to 0.541 meters, based on the minimum CUBE depth (9.896 meters) and maximum CUBE depth (15.916 meters). Results from the SABER Check PFM Uncertainty function identified that there was one node in the final H13217 one-meter PFM CUBE surface with vertical uncertainties that exceeded IHO Order 1a allowable vertical uncertainty for a specific node. This node was within the sheets calculated allowable uncertainty. This single node was associated with an obstruction (Feature 3) which was submitted as DTON 01. The SABER Frequency Distribution Tool was also used to review the Hyp. Final Uncertainty surface within the final H13217 one-meter PFM grid, and the results showed that in the final one-meter PFM grid, 100.00% of all nodes had final uncertainties less than or equal to 0.526 meters.Per the Project Instructions, analysis of the H13217 junction with an adjacent survey was performed as detailed in Table 7. Figure 7 shows the general locality of H13217 as it relates to adjacent surveys. Comparisons were not performed against H13218, as processing efforts for that sheet were still on-going. Refer to Separates II for details about how the junction analysis was performed and a complete discussion of the analysis and tabular results.General Locality of H13217 with Junctioning SurveysSupportFiles\H13217_Figure_07.jpgH10835200001999Leidos (formerly SAIC)WH13217 junctions with H18035 to the west; 100% of the comparisons agreed within ±0.813 meters or less while 91.10% of the comparison results fell within the allowable uncertainties (calculated to be between 0.522 to 0.541 meters for the range of depths observed in the comparison area; 11.433 to 15.876 meters).Sonar system quality control checks were conducted as detailed in the DAPR and quality control checks conducted during H13217 are reported in Separates I.None ExistThere were no conditions or deficiencies that affected equipment operational effectiveness.None ExistThere were no other factors that affected corrections to soundings.On the M/V Atlantic Surveyor, the MVP30 was the primary system used to collect sound speed profile (SSP) data, refer to the DAPR for additional details. SSP data were obtained at intervals frequent enough to meet depth accuracy requirements. All sound speed profiles applied for online bathymetry data collection were acquired within 500 meters of the bounds of the survey area as specified in Section 5.2.3.3 of the HSSD. Confidence checks of the sound speed profile casts were conducted by comparing at least two consecutive casts taken with different SSP sensors. Three sound speed confidence checks were conducted during H13217 and the results can be found in Separates II within the “Comparison Cast Log” section. All individual SSP files are delivered with the H13217 data and are broken out into sub-folders, which correspond to the purpose of each cast. Also, all individual SSP files for H13217 have been concatenated into four separate files based on the purpose of the cast, provided in CARIS format files (.svp), and delivered under (H13217/Processed/SVP/CARIS_SSP) on the delivery drive. In addition, sound speed data for the entire OPR-K371-KR-19 project will be submitted to NCEI following the NetCDF template format as specified in Section 8.3.6 of the HSSD.All equipment and survey methods are detailed in the DAPR.Multibeam Coverage AnalysisLeidos chose to achieve the coverage requirement using 100% side scan sonar coverage with concurrent multibeam bathymetry. To achieve this coverage, the M/V Atlantic Surveyor used a towed Klein 3000 SSS set to 75-meter range scale. Mainscheme line spacing was set to 120 meters, which ensured 100% SSS coverage. Assigned item disproval areas outside of the main survey statement of work area were planned utilizing a SSS range scale of 50 meters. To ensure 200% coverage the line spacing in these areas was set at 40 meters. The HSSD Section 7.3.4 stated that 100% SSS coverage was insufficient to disprove a charted feature. Therefore, Leidos reviewed the Composite Source File (CSF), BSB charts, and ENC charts and completed an additional 100% SSS coverage, and resulting MBES coverage over assigned objects not found during survey in order to verify disproval. A disproval search area was developed as specified in the Project Reference File (PRF), Final_OPR-K371-KR-19_PRF.000 (provided on 18 March 2019), or following best practices if not specified. The disproval areas are documented within the H13217 S-57 FFF. For all assigned objects within the H13217 Statement of Work (SOW), each object’s achieved disproval data covered an area of at least what was assigned. The SABER Gapchecker program was used to flag MBES data gaps within the CUBE surface. Additionally, the entire surface was visually scanned for holidays at various points during the data processing effort. Additional survey lines were run to fill any holidays that were detected. A final review of the CUBE Depth surface of the H13217 one-meter PFM showed that there were no holidays as defined for complete coverage surveys in Section 5.2.2.3 of the HSSD. The final H13217 CUBE PFM was examined for the number of soundings contributing to the chosen CUBE hypotheses for each node by running SABER’s Frequency Distribution Tool on the Hypothesis Number of Soundings (Hyp. # Soundings) surface. The Hyp. # Soundings surface reports the number of soundings that were used to compute the chosen hypothesis. Analysis of the Hyp. # Soundings surface of the final H13217 one-meter PFM, revealed that 99.63% of all nodes contained five or more soundings; satisfying the requirements for complete coverage surveys, Option B, as specified in Section 5.2.2.3 of the HSSD.All data reduction procedures conform to those detailed in the DAPR.All sounding systems were calibrated as detailed in the DAPR.Side Scan Sonar (SSS) Coverage Analysis: For all details regarding SSS data processing, see the DAPR. Leidos chose to adhere to the coverage requirements in the Project Instructions using Complete Coverage, Option B (100% side scan sonar coverage with concurrent multibeam). The HSSD stated that 100% SSS coverage was insufficient to disprove a charted feature. Therefore, 100% SSS coverage was collected and verified for the entire survey area, and an additional 100% SSS coverage was collected over CSF assigned objects that were not found, to verify disproval. Leidos generated two separate coverage mosaics at one-meter cell size resolution as specified in Section 8.2.1 of the HSSD. The first 100% and second 100% disproval coverage mosaics were independently reviewed using tools in SABER to verify data quality and swath coverage. The SABER Gapchecker routine was used to flag data gaps within each of the 100% SSS coverage mosaics. Additionally, the entirety of each SSS surface was visually scanned for holidays at various points during the data processing effort. Additional survey lines were run to fill any holidays that were detected. Both coverage mosaics are determined to be complete and sufficient to meet the requirements contained within the Project Instructions and HSSD. Each 100 percent coverage mosaic is delivered as a single georeferenced raster file in floating point GeoTIFF format, as specified in Sections 8.2.1 and 8.3.3 in the HSSD. Multibeam Echo Sounder Seafloor Backscatter: In accordance with the HSSD Section 6.2, Leidos collected MBES backscatter with all GSF data acquired. The MBES settings used were checked to ensure acceptable quality standards were met and to mitigate acoustic saturation of the backscatter data. The MBES backscatter data acquired were written to the GSF in real-time by ISS-2000 and are delivered in the final GSF files for this sheet. Per HSSD Section 6.2.1, as the Project Instructions did not state to evaluate the backscatter data, backscatter data were not processed by Leidos and no additional products were produced.LeidosSABER5.4.0.22.3LeidosSABER5.4.0.22.4NOAA Extended Attribute File V5-4The primary data processing software used for both bathymetry and imagery was SABER. Subsequent to the delivery of the OPR-K371-KR-19 DAPR (submitted 2019-12-06), the SABER version was upgraded from 5.4.0.22.3 to 5.4.0.22.4 as captured in Table 9. There were no other changes from the software configuration as detailed in the DAPR.H13217_MB_1m_MLLW_Final-1_of_4BAG114.56715.916N/AComplete Coverage, Option B (100% side scan sonar coverage with concurrent multibeam)H13217_MB_1m_MLLW_Final-2_of_4BAG112.78415.022N/AComplete Coverage, Option B (100% side scan sonar coverage with concurrent multibeam)H13217_MB_1m_MLLW_Final-3_of_4BAG19.89614.336N/AComplete Coverage, Option B (100% side scan sonar coverage with concurrent multibeam)H13217_MB_1m_MLLW_Final-4_of_4BAG110.53513.306N/AComplete Coverage, Option B (100% side scan sonar coverage with concurrent multibeam)H13217_SSSAB_1m_100kHz_1of2SSS Mosaic (.tif)10.000.00N/A100% SSSH13217_SSSAB_1m_100kHz_2of2SSS Mosaic (.tif)10.000.00N/ASecond 100% SSS For Object DisprovalComplete Coverage Section 5.2.2.3 of the HSSD requires one-meter node resolution for depths ranging from zero meters to 20 meters. Leidos generated CUBE PFM grids for H13217 at one-meter resolution. The CUBE Depth surface of the final H13217 one-meter PFM (containing all valid depth data) was used to assess and document multibeam survey coverage. SABER populates the CUBE depth with either the node’s chosen hypothesis or the depth of a feature or designated sounding set by the hydrographer, which overrides the chosen hypothesis. The range of CUBE depths of the H13217 one-meter PFM was from 9.896 meters (32.467 feet; 0.260 meters Total Vertical Uncertainty [TVU]) to 15.916 meters (52.218 feet; 0.260 meters TVU). The final gridded bathymetry data are delivered as a Bathymetric Attributed Grid (BAG). The BAG files were exported from the CUBE PFM grid as detailed in the DAPR.For the purposes of grid management, the Branch has created a single H13217_MB_1m_MLLW_1of1.bag that replaces the H13217_MB_1m_MLLW_Final-X_of_3 multibeam bathymetry grids submitted by the field unit. The H13217_MB_1m_MLLW_1of1.bag is the final deliverable to be used in charting products and for archive.Additional information discussing the vertical and horizontal control for this survey can be found in the DAPR.Mean Lower Low WaterERS via VDATUMOPR-K371-KR-19_NAD83_VDatum_MLLW.covRefer to the DAPR for details regarding the application of VDatum to the MBES data files. No final tide note was provided from NOAA Center for Operational Oceanographic Products and Services (CO-OPS). While a final tide note was not required, a final tide note has been provided by Leidos in Appendix I.North American Datum 1983Projected UTM 15The vessel kinematic data (POS/MV files) were post-processed in Applanix POSPac software using the Applanix PP-RTX solution to generate the Smoothed Best Estimate of Trajectory (SBET) solutions which were applied through SABER to the multibeam data. Refer to the DAPR for additional information and for details regarding all antenna and transducer offsets. Any soundings with total horizontal uncertainties exceeding the maximum allowable IHO S-44 5th Edition Order 1a specifications were flagged as invalid and therefore were not used in the CUBE depth calculations.The chart comparisons were conducted using a combination of SABER and CARIS’ HIPS and SIPS. United States Coast Guard (USCG) District 8 Local Notice to Mariners (LNM) publications were reviewed for changes subsequent to the date of the Project Instructions and before the end of survey (as specified in Section 8.1.4 of the HSSD). The LNM reviewed were from week 13/19 (27 March 2019) until week 52/19 (23 December 2019). H13217 data met data accuracy standards and bottom coverage requirements. Leidos recommends updating the common areas of all charts using data from this survey. Charting recommendations for new features, and updates to charted features, are documented in the H13217 S-57 FFF. Additional charted objects such as submarine pipelines and platforms are discussed in later sections.US4TX52M80000292019-12-092019-12-09falseENC US4TX52M covers the extents of H13217 survey area with the exception of the western most assigned disproval area for a charted Wreck. CUBE depths within H13217 were generally within 0.5 meters of the charted depths across the contemporaneous survey area and tended to be shoaler than the charted soundings (Figure 8). There were no depth contours on ENC US4TX52M that fell within the H13217 survey area. ENC US4TX52M Charted Soundings (red) with H13217 CUBE Depth Selected Soundings (black)SupportFiles\H13217_Figure_08.jpgUS5TX53M25000582019-11-052019-11-05falseENC US5TX53M covers the western most disproval area of H13217 survey area. CUBE depths within the disproval area for H13217 were generally shoaler than charted depths, with observed differences of 0.30 - 0.50 meters (Figure 9). There were no depth contours on ENC US4TX53M that fell within the H13217 survey area.ENC US4TX53M Charted Soundings (red) with H13217 CUBE Depth Selected Soundings (black)SupportFiles\H13217_Figure_09.jpgNo Maritime Boundary Points were assigned for this survey.There were seven charted features assigned (2 obstructions and 5 wrecks) in the final CSF (Final_OPR-K371-KR-19_CSF.000) that fell within H13217. The one charted wreck on ENC US5TX53M was the western most assigned feature in H13217. The assigned disproval area was covered by 200% SSS and resulting MBES data. A wreck was not observed within the assigned disproval area. The remaining four assigned wreck features were associated with ENC US4TX52M. The assigned disproval areas were covered by 200% SSS and resulting MBES data except when noted in the H13217 S-57 FFF. No wrecks were identified within the assigned disproval areas, however obstructions (as discussed below and addressed in the H13217_FFF.000) were observed in three of the four assigned areas. Within the northern most assigned wreck disproval area, a 2.5 by 4.8 meter obstruction with a height of 1.17 meters (Feature 01) was observed in MBES and SSS data. The observed obstruction was located approximately 140 meters southwest of the charted wreck PA. Within the southeastern most wreck disproval area, a 2.9 by 2.5 meter obstruction with a height of 1.25 meters (Feature 02) was identified. The observed obstruction was located approximately 330 meters northwest of the charted wreck PA. Within the central wreck disproval area, a 4.5 by 4 meter obstruction with a height of 1.84 meters (Feature 07) was identified. The observed obstruction was located approximately 280 meters south southeast of the charted wreck PA. This obstruction was submitted as DTON and Anti-DTON 03. The two assigned obstructions, both with a category of “wellhead”, were both associated with ENC US4TX52M. Both assigned feature disproval areas were covered with 200% SSS and resulting MBES data. There were no wellhead obstructions found within either disproval area. One additional feature was charted with in H13217 survey area, identified as an obstruction with a least depth of 9.7 meters. This feature was not assigned as it resulted from H21317 DTON 01 submission. See section D.1.5 and H13217 S-57 FFF for further details and recommendations.See the H13217 S-57 FFF for all the details and recommendations regarding new uncharted features investigated.There were no significant shoals or hazardous features within the area covered by this survey other than those discussed in Section D.1.4. Leidos submitted four DTONs for H13217. Each DTON was submitted in S-57 format to the Atlantic Hydrographic Branch (AHB). 1. DTON 01 was submitted on 16 August 2019, for an uncharted obstruction. This DTON was submitted to Nautical Data Brach (NDB) and Marine Chart Division (MCD) on 19 August 2019. 2. DTON 02 was submitted on 31 December 2019, for an uncharted obstruction. This DTON was submitted to NDB and MCD on 31 December 2019. 3. DTON 03 and Anti-DTON were submitted on 31 December 2019, for an uncharted obstruction 275m SSE of a charted wreck PA. This DTON was submitted to NDB and MCD on 02 January 2020. 4. DTON 04, submitted on 31 December 2019, contained eight separate exposed uncharted pipelines which were submitted as DTONs in accordance with HSSD Section 1.6.2.4. This DTON was submitted to NDB and MCD for charting consideration based upon the vertical rise for two of the eight exposed pipeline sections. The remaining six uncharted exposed pipelines were not recommended for chart application. A copy of the email correspondence for Leidos’ submissions of H13217 DTON Reports, as well as the DTON recommendation file and verification email from NDB, are included within Appendix II of this Descriptive Report. Figure 10 details the submitted DTONs and the associated Feature number and object class in the S-57 FFF.DTON ReportsSupportFiles\H13217_Figure_10.jpgThere were no channels within the area covered by this survey.In accordance with both the Project Instructions and Section 7.2.3 of the HSSD, bottom characteristics were obtained for H13217. Bottom characteristics were acquired at the four locations assigned in the PRF by NOAA. Leidos did not modify the bottom sample locations from the location proposed by NOAA in the PRF. Bottom characteristics collected during H13217 are included in the H13217 S-57 FFF, named H13217_FFF.000, within the Seabed Area (SBDARE) object, and are classified according to the requirements set forth in the HSSD. In addition, images of the sediment obtained for each bottom sample are referenced in the H13217_FFF.000 and are included on the delivery drive under the folder H13217/Processed/Multimedia.All features in the CSF within the assigned Survey Limits of H13217 were resolved. There were no assigned features inshore of the NALL.There were no aids to navigation that fell within this survey area.There were no overhead features within this survey area.Refer to Section D.1.5, as H13217 DTON 04 contained eight sections of exposed uncharted pipelines. These pipelines are included in the S-57 FFF. One seep was found within the bounds of H13217; in accordance with HSSD Section 1.7, the seep was submitted in a Seep Report. The email correspondence for Leidos’ submission of the H13217 Seep Report is included within Appendix II of this Descriptive Report. The seep identified within the MBES data of H13217 had a form and morphology typical of ascending gas or bubble plumes. The seep was not associated with a section of charted or identified uncharted pipeline however was approximately 175 meters WSW of a platform (Feature 17). The MBES data associated with the seep have been flagged as invalid and therefore were not used in the CUBE depth calculations.There were thirteen assigned offshore platform objects in the CSF, Final_OPR-K371-KR-19_CSF.000, which fell within the SOW for H13217. All of the assigned platforms were charted on ENC US4TX52M. Investigation requirements for assigned platforms within the CSF, Final_OPR-K371-KR-19_CSF.000, stated to “Visually confirm feature object existence. If feature exists, include in FFF with descrp=retain. If feature is not visible, conduct a feature disproval (Section 7.3.4).” Of the thirteen charted platforms assigned within the survey area for H13217, six platforms were visible above the waterline. The remaining seven assigned charted platforms were not found during survey operations therefore disproval surveys were conducted. The disproval surveys were conducted by collecting 200% SSS and resulting MBES over an area centered at the CSF platform position with a radius of at least 80 meters. Within the disproval radii, there was no evidence of a platform in the SSS or MBES data. For platforms visible above the waterline, the surveyed position was derived from either the SSS or MBES data. Regardless of the source of the position, there were attribution revisions observed from survey data to the data from the CSF. In conjunction with the CSF investigation requirements Leidos also followed direction from HSSD Section 7.5.2: • “Update = Modification to attribution, geometry, and/or feature object class” • “1. Charted feature is found in new position via multibeam… regardless of proximity to charted feature” When the final position was derived from MBES data, the data from H13217 was input into the S-57 FFF with a descrp of New and the corresponding platform from the CSF had a descrp of Delete. When the final position was derived from SSS data only, the positions within the S-57 FFF were retained from the position provided in the CSF. For these platforms, the descrp were set to Update; as there were attribution modifications observed during H13217. The attributes modified are documented within the S-57 FFF. Figure 11 details the position provided from the CSF as well as each position, when present, from the H13217 data. The position within the S-57 FFF only differed from the CSF in one instance, listed in the Figure 11 with descrp DELETE/NEW. The descrp Update only refers to attributes being modified within the S-57 FFF. See the S-57 FFF, named H13217_FFF.000, Offshore Platform (OFSPLF) objects, for details and charting recommendations. Platforms within H13217SupportFiles\H13217_Figure_11.jpgNo ferry routes or terminals exist within this survey area.No abnormal seafloor or environmental conditions, as defined in Section 8.1.4 of the HSSD, exist within this survey area.No construction or dredging exists for this survey area.Designated SoundingsSeparate flags exist in the Generic Sensor Format (GSF) for a designated sounding and feature. During data analysis, designated soundings or feature flags are used to help better preserve the shoalest sounding relative to the computed depth surface. All depths flagged as features and designated soundings override the CUBE best estimate of the depth in the final BAG files. Both the designated sounding and feature flags, as defined within GSF, are mapped to the same HDCS flag when ingested into CARIS (PD_DEPTH_DESIGNATED_MASK). GSF feature flags were set on significant features within H13217, and all information is contained in the H13217 S-57 Final Feature File (FFF).Final Feature S-57 FileIncluded with the H13217 delivery is the S-57 FFF, H13217_FFF.000. Details on how this file was generated and quality controlled can be found in the DAPR. The S-57 FFF delivered for H13217 contains millimeter precision for the value of sounding (VALSOU) attribute. As specified in Section 2.2 of the HSSD, the S-57 FFF is in the WGS84 datum and is unprojected with all depth units in meters. All significant and recommended for charting features found in H13217 are included within the S-57 FFF. In accordance with the HSSD, Leidos addressed all assigned objects from the provided CSF S-57 file that fell within the bounds of H13217 in the S-57 FFF. For each feature set within the H13217 data, a Feature Correlator Sheet was exported as an image file (.jpg) and is included in the S-57 FFF under the NOAA Extended Attribute field “images”.Side Scan Sonar Contacts S-57 FileIncluded with the H13217 delivery is the Side Scan Sonar Contact S-57 File, H13217_SSCon.000. Details on how this file was generated and quality controlled can be found in the DAPR. As specified in Section 2.2 of the HSSD, the S-57 file is in the WGS84 datum and is unprojected with all depth units in meters. Side scan sonar contacts were investigated and confirmed using SABER Contact Review. All side scan contacts are retained within the Side Scan Sonar Contact S-57 File. For each contact included in this S-57 file, a JPEG image of the side scan contact is included under the NOAA Extended Attribute field “images”.Coast Pilot Review ReportIn accordance with the Project Instructions and HSSD Section 8.1.3, a Coast Pilot Review was performed for OPR-K371-KR-19. Within the Coast Pilot Field Report (OPR-K371-KR-18CoastPilotReport.pdf) provided by NOAA to Leidos on 18 March 2019, it indicated that paragraphs 15 through 127 were relevant to the survey area of OPR-K371-KR-19 and there were no assigned investigation items. During survey, Leidos reviewed and updated the assigned and additional Coast Pilot paragraphs as possible for the survey area, port of call, and areas frequently transited. Leidos downloaded Coast Pilot 5 Chapter 10 from the Coast Pilot website, 47th Edition of Coast Pilot 5, dated 17 November 2019. Recommendations were documented using the text from the 47th Edition and are marked following the HSSD Section 8.1.3. Leidos followed NOAA’s strategy for designating omitted paragraphs as provided in the delivered Coast Pilot Field Report (OPR-K371-KR-18CoastPilotReport.pdf). Leidos submitted the Coast Pilot Field Report on 22 November 2019. The email correspondence for Leidos’ submission of the Coast Pilot Review Report is included within the Project Correspondence.No new survey recommendations are made for the area surrounding this survey area.No inset recommendations are made for the area covered by this surveyAs Chief of Party, field operations for this hydrographic survey were conducted under my direct supervision, with frequent personal checks of progress and adequacy. I have reviewed the attached survey data and reports.This Descriptive Report, all BAG files, and all accompanying records and data are approved. All records are forwarded for final review and processing to the Processing Branch.The survey data meets or exceeds requirements as set forth in the Hydrographic Surveys Specifications and Deliverables, Project Instructions, and Statement of Work. These data are adequate to supersede charted data in their common areas. This survey is complete and no additional work is required. Previously, or concurrently, submitted deliverables for OPR-K371-KR-19 are provided in the table below.Paul L. DonaldsonChief Hydrographer2020-01-14OPR-K371-KR-19_Coast Pilot Review Report.pdf 2019-11-22OPR-K371-KR-19_Marine_Species_Awareness_Training_Record.pdf2019-11-22OPR-K371-KR-19_DAPR.pdf2019-12-06H13213_DR.pdf2019-12-06H13214_DR.pdf2019-12-13H13216_DR.pdf2019-12-20H13215_DR.pdf2020-01-06H13217_DR.pdf2020-01-08H13220_DR.pdf2020-01-14H13213_DR_rev1.pdf2020-01-14H13214_DR_rev1.pdf2020-01-14H13215_DR_rev1.pdf2020-01-14H13216_DR_rev1.pdf2020-01-14