OPR-K371-KR-15 Gulf of Mexico Leidos H12730 4 25 NM SE of Sabine Pass Louisiana United States 40000 2015 Paul L. Donaldson Basic Hydrographic Survey 2015-04-09 2015-12-01 2015-12-15 Multibeam Echo Sounder Multibeam Echo Sounder Backscatter Side Scan Sonar meters Universal Transverse Mercator (UTM) UTC Atlantic Hydrographic Branch EA-133C-14-CQ_0033. Contractor: Leidos, 221 Third Street, Newport, RI 02840 USA. Subcontractors: Divemasters, Inc., 15 Pumpshire Road, Toms River, NJ 08753 and OARS, 8705 Shoal Creek Blvd, Suite 109, Austin, TX 78757. Leidos Doc 16-TR-024. All times were recorded in UTC. Data were collected in UTM Zone 15 Contractor The area surveyed was a section of the Gulf of Mexico SE of Sabine Pass, LA (Figure 1) 29.37682 093.63581 29.30201 093.45312 Outline of area surveyed as part of H12827. file:///SupportFiles/H12730_Figure_1.jpg Survey limits were acquired in accordance with the requirements in the Project Instructions and the NOS Hydrographic Survey Specifications and Deliverables (HSSD). The purpose of this survey is to update existing NOS nautical charts. This project is located in a highly trafficked critical area south of the Louisiana coast as designated in the 2012 NOAA Hydrographic Survey Priorities. 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. H12730 was surveyed in accordance with the following documents: 1. Project Instructions, OPR-K371-KR-15, dated 09 April 2015 2. NOS Hydrographic Survey Specifications and Deliverables (HSSD), May 2015 3. OPR-K371-KR-15 Statement of Work, dated 09 January 2015 All waters in survey area. Either A) Complete MBES with backscatter, OR B) 100% SSS with concurrent set line spacing with MBES with backscatter. Note: Complete MBES is sufficient for both determination of least depth identified with SSS and for disproving a feature - 100% SSS is sufficient to disprove a feature. Refer to Section 6.1.2 of the HSSD to confirm proper SSS acquisition parameters. Gaps in SSS coverage should be treated as gaps in MBES coverage and addressed accordingly. Leidos chose to achieve the coverage requirement using 100% side scan sonar with concurrent set line spacing multibeam echo-sounder with backscatter. Survey coverage was in accordance with the requirements in the Project Instructions and the HSSD. Final Bathymetry Coverage for H12730 file:///SupportFiles/H12730_Figure_2.jpg M/V Atlantic Surveyor 0 0 0 0 0 1048.87 0 84.35 0 2802 0 8.58 0 0 0 82.03 0 0 0 0 0 0 0 1048.87 0 84.35 0 8.04 7 0 0 0 41.65 2015-12-01 2015-12-02 2015-12-03 2015-12-04 2015-12-05 2015-12-06 2015-12-07 2015-12-08 2015-12-10 2015-12-15 Leidos 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 6 Linux platforms. L-3 Klein 3000 side scan data were collected on a Windows 7 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-K371-KR-15, delivered on 12 February 2016. There were no variations from the equipment configuration described in the DAPR. M/V Atlantic Surveyor 110 9 The M/V Atlantic Surveyor was used to collect multibeam sonar (RESON Seabat 8101 ER), 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 DAPR. RESON Seabat 8101 ER MBES L-3 Klein 3000 SSS Applanix POS/MV 320 Positioning and Attitude System Trimble Probeacon Positioning System Brooke Ocean Technology MVP-30 Sound Speed System There were 84.35 linear nautical miles of crosslines and 1048.87 linear nautical miles of mainscheme lines surveyed on H12730. This resulted in crossline mileage of approximately 8.04% of the mainscheme mileage which meets the requirement (Section 5.2.4.3 of the 2015 HSSD) to achieve at least four percent for a complete coverage multibeam survey. H12730 requirements were for complete coverage based on the 2015 HSSD and set line spacing in the 2014 HSSD. Leidos was granted permission from NOAA (correspondence email dated 26 October 2015) to deliver H12730 data to the 2015 HSSD version after survey operations had already commenced; therefore, crossline survey plans were made to the 2014 HSSD requirement of eight percent. The mainscheme lines were orientated 90°/270° and spaced 80 meters apart. Crosslines were oriented 0°/180° and spaced 975 meters apart. Refer to the “Multibeam Processing Log” section within Separates I for information on the delineation of mainscheme and crossline data files. In the field, hydrographers conducted daily comparisons of mainscheme to near nadir crossline data to ensure that no systematic errors were introduced, and to identify potential problems with the survey systems. After the application of all correctors and completion of final processing in the office, separate one-meter grids were built. One grid contained the full valid swath (±60° from nadir) of mainscheme multibeam and the other included only the near nadir swath (±5° from nadir) crossline data. Difference grids were then generated by subtracting one grid from the other. The SABER Frequency Distribution Tool was used to analyze the difference grids. All comparisons fell 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. Figure 3 summarizes the comparison results. See Separates II for a complete discussion of the analysis and tabular results. Summary of Crossing Analysis file:///SupportFiles/H12730_Figure_3.jpg 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. 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. AvgTPE). 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. For specific details on this process see Section B.2 of the DAPR. The final one-meter PFM CUBE surface contained final vertical uncertainties that ranged from 0.470 to 1.235 meters. The IHO Order 1a maximum allowable vertical uncertainty was calculated to range between 0.516 to 0.545 meters, based on the minimum CUBE depth (9.792 meters) and maximum CUBE depth (16.723 meters). The SABER Check PFM Uncertainty function was used to highlight all instances in the Hypothesis Final Uncertainty surface where a given node exceeded the IHO Order 1a allowable vertical uncertainty for the CUBE depth at that node. The final one-meter PFM CUBE surface contained 110 individual CUBE nodes with final vertical uncertainties that exceeded IHO Order 1a allowable vertical uncertainty. The nodes that exceed the IHO Order 1a allowable vertical uncertainty for the CUBE depth are primarily located around features where there is a high variability in the depth soundings. There were four nodes where the uncertainty was high resulting from lines that were re-run due to gaps in the CUBE surface. The SABER Frequency Distribution Tool was used to review the Hypothesis Final Uncertainty surface within the final one-meter PFM grid. The results show that in the final one-meter PFM grid, 99.99% of all nodes had final uncertainties less than or equal to 0.500 meters. An analysis of H12730 junctions with contemporary surveys was performed. Figure 4 shows the general locality of H12730 as it relates to the contemporary sheets for which junction analysis was performed. Table 6 provides details for each contemporary sheet junction analysis performed. See Separates II for a complete discussion of the junction results and tabular listings. Note that analysis of the junction with H12731 was not conducted, as at the time of this delivery, Leidos had not begun data acquisition of H12731. General Locality of H12730 with Contemporary Surveys file:///SupportFiles/H12730_Figure_4.jpg >H10804 20000 1999 John E. Chance and Associates W H12730 junctions with H10804 to the west; 96.86% of the comparisons agreed within ±0.50 meters. H10948 20000 2000 Fugro GeoServices, Inc. SW H12730 junctions with H10948 to the southwest; 98.38% of the comparisons agreed within ±0.65 meters. H12728 40000 2015 Leidos N H12730 junctions with H12728 to the north; 98.42% of the comparisons agreed within ±0.18 meters. Sonar system quality control checks were conducted as detailed in Section A.5, Multibeam Systems and Operations, of the DAPR. None Exist There were no conditions or deficiencies that affected equipment operational effectiveness. Exist During localized weather events, an artifact resulting from a difference in water levels between the survey area and the water level gauge was observed in the multibeam CUBE surface. The artifact generally ranged between 10 to 20 centimeters when present (Figure 5). The occasional vertical offsets observed within H12730 were within the IHO Order 1a allowable vertical and horizontal uncertainty for these water depths. CUBE Depth Delta Resulting From Local Weather Events file:///SupportFiles/H12730_Figure_5.jpg 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. All sound speed profiles that were applied for online bathymetry data collection were acquired within one kilometer of the bounds of the survey area. Please refer to the DAPR for specific details regarding acquisition (Section A.7) and application (Section C.1.3) of sound speed profiles. Confidence checks of the sound speed profile casts were conducted by comparing at least two consecutive casts taken with different SVP Smart Sensors. Five sound speed confidence checks were conducted during H12730 and the results can be found in Separates II within the “Comparison Cast Log” section. Sound speed profiles have been provided in CARIS format (.svp) and are named based on the purpose of the casts. There were four distinct purposes for SSP casts and each concatenated SSP file is located in a separate folder on the delivery drive (H12730/Data/Processed/SVP/CARIS_SSP). There are four files for the MVP sound speed data. All individual sound speed profile files are also delivered with the H12730 data and are broken out into sub-folders, which correspond to the purpose of each cast. All equipment and survey methods are detailed in the DAPR. Coverage Analysis Leidos chose to achieve the coverage requirement using 100% side scan sonar with concurrent set line spacing multibeam echo-sounder with backscatter. To achieve this coverage, the M/V Atlantic Surveyor used a towed L-3 Klein 3000 side scan sonar set to a 50-meter range scale. Mainscheme line spacing was 80 meters, which insured 100% side scan coverage. Both the Project Instructions and the HSSD stated that 100% side scan was insufficient to disprove a charted feature. Therefore, Leidos reviewed the BSB and ENC charts and completed an additional 100% side scan coverage, and resulting multibeam coverage over common charted objects not found during survey in order to verify disproval. A radius was determined from the Project Instructions, which stated, “In the case of the unassigned offshore oil platforms within the survey area, should the field unit observe that the feature is not visible, then a formal disproval is required. For the purposes of disproval, charted features labeled with a "PA" will have a search radius of 160 meters, a "PD" will have a search radius of 240 meters, and all other features without a position qualifier will have a search radius of 80 meters.” Backscatter data were acquired for all water depths. The SABER Gapchecker routine was used to flag multibeam 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 one-meter PFM containing all multibeam showed that there were a few areas where a three by three node gap exists. These gaps resulted from one of two reasons, the holiday line data was offset slightly from the original line due to vessel line following or the swath width of the holiday lines were reduced compared to the original line due to water level differences. One instance of a three by three node gap, 29° 21’ 20.97”N 093° 35’ 44.17”W, exists on a crossline where data were turned off, and additional crossline data were not needed, as the crossline percentage requirement had already been met. 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 for the one-meter PFM. The Hyp # Soundings surface reports the number of soundings that were used to compute the chosen hypothesis. Analysis of the H12730 final one-meter PFM grid revealed that 87.59% of all nodes contained five or more soundings; satisfying the requirements for complete coverage surveys, as specified in Section 5.2.2.2 of the HSSD. 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 HSSD and Project Instructions, Leidos collected multibeam backscatter with all GSF data acquired by the RESON Seabat 8101 ER. The multibeam settings used were checked to ensure acceptable quality standards were met and to avoid any acoustic saturation of the backscatter data. The multibeam 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. Backscatter was not processed by Leidos. Leidos SABER 5.2.0.14.13 Leidos SABER 5.2.0.14.13 NOAA Extended Atribute File V5-2. The primary data processing software used for both bathymetry and imagery was SABER. There were no software configuration changes after the DAPR was submitted. H12730_MB_1m_MLLW BAG 1 9.792 16.723 N/A Complete Coverage H12730_ss_1_100_mosaic SSS Mosaic (.tif;.tfw) 1 0 0 N/A 100% SSS H12730_ss_2_100_mosaic SSS Mosaic (.tif;.tfw) 1 0 0 N/A 200% SSS Charted Object Disproval A 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 H12730 was from 9.792 meters (32.126 feet, 0.480-meter uncertainty) to 16.723 meters (54.865 feet, 0.480-meter uncertainty). Section 5.2.2.2 of the HSSD requires a one-meter grid resolution for depths ranging from zero meters to 20 meters for Complete Coverage. The final gridded bathymetry data are delivered as Bathymetric Attributed Grids (BAG). The BAG file was exported from the CUBE PFM grid as detailed in Section B.2.5 of the DAPR Side Scan Coverage Analysis For all details regarding side scan data processing, see Section B.3 of the DAPR. The Project Instructions required 100% side scan coverage with concurrent set line spacing MBES with backscatter. Both the Project Instructions and the HSSD stated that 100% side scan was insufficient to disprove a charted feature. Therefore, 100% side scan coverage was collected and verified for the entire survey area, and an additional 100% coverage was collected over charted objects that were not found to verify disproval. Leidos generated 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), refer to Table 7. 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; for specifics refer to Section D.2.13. No vertical or horizontal controls were established, recovered, or occupied during data acquisition for OPR-K371-KR-15, which includes H12730. Therefore, a Horizontal and Vertical Control Report was not required Mean Lower Low Water Discrete Zoning Calcasieu Pass, LA 8768094 8768094_verified_09222015_to_12202015.tid Verified Observed K371KR2015CORP.zdf Final 1957-08-13 1957-08-15 No 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 H12730 however, a final tide note has been provided by Leidos in Appendix I. The Tides Statement of Work specified NOAA tide station 8768094 Calcasieu Pass, LA as the source for water level correctors for OPR-K371-KR-15. A full explanation of the tide zone assessment is detailed in Section C.4 of the DAPR. For H12730, 8768094 Calcasieu Pass, LA was the source of all final verified water level heights for determining correctors to soundings. All data for H12730 were contained within three tide zones (WGM72, WGM407, and WGM81) which were provided from NOAA. Leidos did not revise the delivered tide zones for tide station 8768094 Calcasieu Pass, LA as the water level zoning parameters in the file K371KR2015CORP.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 H12730 bathymetry data. Leidos was notified on 14 January 2016 that an adjustment to the observed verified tide correctors posted on the CO-OPS website were changed due to an adjustment of the sensor elevation during maintenance of the sensor. This change modified the observed verified correctors from September 2015 through December 2015. Leidos downloaded these changes and applied the updated verified tides to all data within H12730. North American Datum of 1983 (NAD83) UTM Zone 15 Smart Base English Turn, LA (293 kHz) Angleton, TX (301 kHz) Aransas Pass, TX (304 kHz) Please refer to the DAPR for details regarding all antenna and transducer offsets. 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 were not used in the CUBE Depth calculations. The chart comparisons were conducted using the Leidos SABER software to view the BSB raster charts with overlain data for H12730 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). 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 8 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 36/15 (09 September 2015) until week 10/16 (09 March 2016). H12730 data meet data accuracy standards and bottom coverage requirements. Recommend updating the common areas of all charts using data from this survey. Charting recommendations for all features are provided in the S-57 Final Feature File. 11341 124 80000 44 2013-03 2016-02-16 2016-02-20 Chart 11341 covers the entire H12730 survey area. CUBE depths within sheet H12730 agreed with the charted depths across most of the survey area and were generally within ±3 feet of the charted depths. There were discrete areas where the depths varied as much as 11 feet such as in 29° 20’ 43.17”N 093° 33’ 31.87”W. The charted 30-foot depth curve around a 28 foot sounding centered in approximately 29° 18’ 47.34”N 093° 34’ 52.51”W was found to have depths between 32 to 35 feet. Additional charted objects such as submarine pipelines and platforms are discussed in the sections below. All new uncharted features found, and updates to charted features, are documented in the Final Feature File (S-57). US4LA10M 700000 7 2011-05-02 2014-11-13 false In the area of survey H12827, Electronic Navigation Chart (ENC) US2AK92M coincides with Chart 16005, therefore a comparison between H12827 and US2AK92M is equivalent to the preceding comparison with Chart 16005. US4LA10M 80000 10 2014-11-03 2016-01-21 false ENC US4LA10M covers the H12730 survey area, east of 093° 34’ 00.63”W. CUBE depths within sheet H12730 agreed with the charted depths across most of the survey area and were generally within ±1 meter of the charted depths. There were discrete areas where the depths varied as much as 3 meters such as in 29° 20’ 42.64”N 093° 33’ 32.35”W. Additional charted objects such as submarine pipelines and platforms are discussed in the sections below. All new uncharted features found, and updates to charted features, are documented in the Final Feature File (S-57). US4TX71M 80000 27 2016-02-05 2016-02-05 false ENC US4TX71M covers the H12730 survey area, west of 093° 34’ 00.63”W. The charted 9.1-meter depth curve around an 8.5 meter sounding centered in approximately 29° 18’ 45.56”N 093° 34’ 53.02”W was found to have depths between 9.8 to 10.7 meters. Additional charted objects such as submarine pipelines and platforms are discussed in the sections below. All new uncharted features found, and updates to charted features, are documented in the Final Feature File (S-57. No Maritime Boundary Points were assigned for this survey. One charted obstruction was located just outside the statement of work area in 29° 21’ 15.00”N 093° 38’ 00.00”W. The charted obstruction was covered with 200% side scan sonar and resulting multibeam over a radius of at least 160 meters. No obstruction was found. See the S-57 Final Feature File (FFF) for all the details and recommendations regarding new uncharted features investigated. No Danger to Navigation Reports were submitted for this survey. There were no Danger to Navigation Reports (DTON) submitted for H12730. Per guidance from AHB (via email correspondence 20 January 2016), exposed pipelines should not to be submitted as DTONs but as Feature Reports, in S-57 format. Leidos submitted two Feature Reports in S-57 format to AHB, which AHB forwarded to the Office of Coast Surveys Navigation Manager. Feature Report 1 contained a seep located at the junction of two charted pipelines. Feature Report 2 contained 15 sections of exposed pipeline of various lengths. These sections are represented by PIPSOL Features 10, 11, 15, 24-30, 33, and 34 in the S-57 FFF. 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. In accordance with both the Project Instructions and Section 7.1 of the HSSD, bottom characteristics were obtained for H12730. Bottom characteristics were acquired at the seven locations proposed in the Project Reference File (PRF) by NOAA. Leidos did not modify any bottom sample locations from the locations provided by NOAA. Bottom characteristics collected during H12730 are included in the H12730 S-57 FFF, H12730.FFF.000, within the Seabed Area (SBDARE) object and are classified according to the requirements set forth in Appendix H of the HSSD All features within the Composite Source File (CSF) were resolved. There were no assigned features inshore of the NALL. Junction analysis with prior surveys H10804, H10948, and H12728 (collected in 1999, 2000, and 2015) was conducted, and the results are presented in Section B.2.4 of this Data Report and Separates II No Aids to Navigation (ATONs) exist for this survey. No overhead features exist for this survey. Nineteen pipeline (PIPSOL) objects are delivered in the S-57 FFF to represent sections of pipelines found within the bounds of H12730, utilizing both multibeam and side scan data. Additional charted pipelines fall within the survey coverage; however, the multibeam and side scan data do not show evidence of them. No ferry routes or terminals exist for this survey. Five platforms were found within the bounds of H12730 all of which were charted. In addition, five charted platforms were not found; an area with a radius of at least 80 meters was covered by 200% side scan and resulting multibeam. The latest 11341 raster chart only has four of the five covered platforms remaining on the chart. In addition, three charted platforms on ENC USTX71M were removed from both 11341 and 11332 raster charts prior to survey. These three charted platforms were covered by 100% side scan sonar and resulting multibeam. There was no evidence of the platforms existence in the side scan or multibeam data and no platforms were visible above the waterline. See the S-57 FFF, H12730.FFF.000, Offshore Platform (OFSPLF) objects, for details and charting recommendations on each platform. No significant features as defined in Section 8.1.4 of the HSSD exist within the H12730 survey area. No present or planned construction or dredging exist within the survey limits. Designated Soundings Designated soundings were used to help better preserve the shallowest sounding relative to the computed depth surface. Separate flags exist in the Generic Sensor Format (version 3.06) for designated soundings and features. All depths flagged as features and designated soundings override the CUBE best estimate of the depth in the final BAG files. Both the designated soundings and features flags as defined within GSF are mapped to the same HDCS flag when ingested into CARIS (PD_DEPTH_DESIGNATED_MASK). Eleven designated soundings were set for H12730 to preserve the least depth on non-significant objects. The difference between the least depth of these objects and the CUBE depth was more than one-half the maximum allowable total vertical uncertainty at that depth. An individual Correlator Sheet for designated soundings and correlated side scan contacts are presented as JPEG files in the Multimedia folder and are named by the feature numbers (Figure 6). List of Designated Soundings set within H12730 file:///SupportFiles/H12730_Figure_6.jpg Final Feature S-57 File Included with H12730 delivery is the S-57 FFF, H12730.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 FFF delivered for H12730 contains millimeter precision for the value of sounding (VALSOU) attribute. As specified in Section 8.2 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 H12730 are included within the S-57 FFF. In accordance with the HSSD, Leidos addressed all assigned objects within the bounds of H12730 from the provided CSF S-57 file in the S-57 FFF. Additionally, all charted objects, derived from the largest scale ENC, are addressed within the S-57 FFF. Note that positions of the objects from the ENC retain the full extents for that object; and therefore some objects extend beyond the H12730 sheet bounds. For each feature contained in the FFF (S-57), the 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 File Included with the H12730 delivery is the Side Scan Sonar Contact S-57 File, H12730.SSCon.000. Details on how this file was generated and quality controlled can be found in Section B.3.5 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. 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”. 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 BAG files, 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 Specifications and Deliverables, Project Instructions, and the OPR-K371-KR-15 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 with the exception of deficiencies noted in the Descriptive Report. Paul L. Donaldson Chief Hydrographer 2016-03-30 OPR-K371-KR-15_DAPR.pdf 2016-02-12 OPR-K371-KR-15_Coast Pilot Review Report.pdf 2016-02-12 H12727_DR.pdf 2016-02-12 H12728_DR.pdf 2016-02-26 H12729_DR.pdf 2016-03-24