OPR-R320-FA-19Vicinity of Cape NewenhamAlaskaNOAA Ship Fairweather (S220)H132392Cape Peirce to Cape NewenhamAlaskaUnited States400002019CDR Marc Moser, NOAANavigable Area2019-04-302019-06-102019-07-13Multibeam Echo SounderMultibeam Echo Sounder BackscattermetersUTCPacific Hydrographic BranchAny 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 3N, MLLW. All references to other horizontal or vertical datums in this report are applicable to the processed hydrographic data provided by the field unit.NOAAThe survey area is located between Cape Peirce and Cape Newenham, Alaska.58.5057356667161.55924980658.6172067778162.139368944Data were acquired to the survey limits in accordance with the requirements in the Project Instructions and the March 2019 NOS Hydrographic Surveys Specifications and Deliverables (HSSD) as shown in Figure 1. In all areas where the 3.5 meter depth contour or the sheet limits were not met, the Navigable Area Limit Line (NALL) was defined as the inshore limit of bathymetry due to the risks of swells, maneuvering the survey vessel in close proximity to the steep and rocky shoreline, or to avoid disturbing nesting bird colonies. An example of such an area is shown in Figure 2.H13239 sheet limits (in blue) overlaid onto Chart 16305SupportFiles\H13239_sheet_limits_image.pngH13239 Example of where the NALL was not reached due to the risks of maneuvering the survey vessel in close proximity to the rocky shoreline and nesting birds near Shaiak IslandSupportFiles\H13239_nall_within_sheet_limits.pngThe purpose of this hydrographic survey is to update National Ocean Service nautical charting products and support commerce to the northern Bristol Bay region. Capes Newenham and Peirce, Alaska are the southwestern corner of the Togiak National Wildlife Refuge and provide habitat to numerous birds and sea mammals. Ship and barge traffic delivering industrial, consumer, and energy products to the communities of northern Bristol Bay, or continuing north to the Etolin Strait must transit around these capes. Marine commerce is critical for the survival of these western Alaskan communities as they are detached from the rest of the state road system. Legacy hydrographic data in this survey area is extremely sparse and was acquired prior to the 1920s. Updating the nautical charts and accurately charting reported shoals by modern hydrographic means is critical for the future safety of regional commerce, local tanker lightering, emergency response, and the protection of the local wildlife. Survey data from this project is intended to supersede all prior survey data in the common area.The entire survey is adequate to supersede previous data.Data acquired in H13239 meet multibeam echo sounder (MBES) coverage requirements for complete coverage, as required by the HSSD. This includes crosslines (see Section B.2.1), NOAA allowable uncertainty (see Section B.2.10), and density requirements (see Section B.2.11).All waters in survey areaComplete CoverageThe entirety of H13239 was acquired with complete coverage, meeting the requirements listed above and in the HSSD. See Figure 3 for an overview of coverage. H13239 survey coverage overlaid onto Chart 16305SupportFiles\H13239_coverage_overview.pngFA 28050493.49000001.650FA 28060326.850000000FA28070268.050000029.780FA 280800.710000014.86001089.100000046.2804.25400038.012019-06-102019-06-112019-06-122019-06-202019-06-212019-06-232019-06-242019-06-282019-07-012019-07-112019-07-122019-07-13Refer to the Data Acquisition and Processing Report (DAPR) for a complete description of data acquisition and processing systems, survey vessels, quality control procedures and data processing methods. Additional information to supplement sounding and survey data, and any deviations from the DAPR are discussed in the following sections.28058.61.128068.61.128078.61.128088.61.1Kongsberg MaritimeEM 2040MBESSea-Bird ScientificSBE 19plus V2Conductivity, Temperature, and Depth SensorTeledyne RESONSVP 71Sound Speed SystemApplanixPOS MV 320 v5Positioning and Attitude SystemAll launches utilize Kongsberg EM 2040 MBES, Applanix POS MV v5 systems for positioning and attitude, Teledyne RESON SVP 71 surface sound speed sensors, and Sea-Bird Scientific 19plus CTD casts.Crosslines were collected, processed and compared in accordance with Section 5.2.4.2 of the HSSD. To evaluate crosslines, a surface generated via data strictly from mainscheme lines and a surface generated via data strictly from crosslines were created. From these two surfaces, a difference surface (mainscheme- crosslines = difference surface) was generated (Figure 4), and is submitted in the Separates II Digital Data folder. Statistics show the mean difference between the depths derived from mainscheme data and crossline data was 0.02 meters (with mainscheme being deeper) and 95% of nodes falling within +/- 0.16 meters (Figure 5). For the respective depths, the difference surface was compared to the allowable NOAA uncertainty standards. In total, 99.5.+% of the depth differences between H13239 mainscheme and crossline data were within allowable NOAA uncertainties.Overview of H13239 CrosslinesSupportFiles\H13239_Crossline_Overview.pngH13239 Crossline and Mainscheme Difference StatisticsSupportFiles\H13239_MB_VR_MLLW_mainscheme_only_H13239_MB_VR_MLLW_crosslines_depth_delta.pngERS via ERTDM0.140280x (all launches)20.5In addition to the usual a priori estimates of uncertainty provided via device models for vessel motion and ERTDM, real-time and post-processed uncertainty sources were also incorporated into the depth estimates of survey H13239. Real-time uncertainties were provided via EM 2040 MBES data, and Applanix Delayed Heave RMS. Following post-processing of the real-time vessel motion, recomputed uncertainties of vessel roll, pitch, gyro and navigation were applied in CARIS HIPS and SIPS via a Smoothed Best Estimate of Trajectory (SBET) RMS file generated in Applanix POSPac.H13239 junctions with four adjacent surveys from this project, H13238, H13240, H13244, H13245, as shown in Figure 6. Data overlap between H13239 and each adjacent survey was achieved, with the exception of H13244, as discussed below. These areas of overlap between surveys were reviewed with CARIS HIPS and SIPS by surface differencing (at equal resolutions) to assess surface agreement. The multibeam data were also examined in CARIS Subset Editor for consistency and agreement. The junctions with H13239 are generally within the NOAA allowable uncertainty in their areas of overlap. For all junctions with H13239, a negative difference indicates H13239 was shoaler, and a positive difference indicates H13239 was deeper.Overview of H13239 junction surveysSupportFiles\H13239_junction_overview.pngH13238400002019NOAA Ship FAIRWEATHERNWSurface differencing in CARIS HIPS and SIPS was used to assess junction agreement between the surface from H13239 and the surface from H13238, shown in Figure 7. The statistical analysis of the difference surface shows a mean of -0.01 with 95% of all nodes having a maximum deviation of +/-0.14 meters, as seen in Figure 8. It was found that 99.5+% of nodes are within NOAA allowable uncertainty.Difference surface between H13239 (gray) and junctioning survey H13238 (pink)SupportFiles\H13239_H13238_junction_surface.pngDifference surface statistics between H13239 and H13238 (4 meter surface)SupportFiles\H13239_MB_4m_MLLW_H13238_MB_4m_MLLW_depth_delta.pngH13240400002019NOAA Ship FAIRWEATHERSWSurface differencing in CARIS HIPS and SIPS was used to assess junction agreement between the surface from H13239 and the surface from H13240, shown in Figures 9, 10, and 11. The statistical analysis of the difference surface shows a mean of 0.07 with 95% of all nodes having a maximum deviation of +/-0.11 meters, as seen in Figure 12. It was found that 99.5+% of nodes are within NOAA allowable uncertainty.Difference surface between H13239 (gray) and junctioning survey H13240 (light brown)SupportFiles\H13239_H13240_junction_surface1.pngDifference surface between H13239 (gray) and junctioning survey H13240 (light brown)SupportFiles\H13239_H13240_junction_surface2.pngDifference surface between H13239 (gray) and junctioning survey H13240 (light brown)SupportFiles\H13239_H13240_junction_surface3.pngDifference surface statistics between H13239 and H13240 (4 meter surface)SupportFiles\H13239_MB_4m_MLLW_H13240_MB_4m_MLLW_depth_delta.pngH13244400002019NOAA Ship FAIRWEATHERSDue to the set line spacing acquisition technique of H13244 proper data overlap was not achieved with this survey. Due to the strong agreement between H13239 data and the other three adjacent surveys, the hydrographer is confident that no significant systematic biases exist in the data collected for this sheet.H13245400002019NOAA Ship FAIRWEATHERNSurface differencing in CARIS HIPS and SIPS was used to assess junction agreement between the surface from H13239 and the surface from H13245, shown in Figure 13. The statistical analysis of the difference surface shows a mean of 0.02 with 95% of all nodes having a maximum deviation of +/-0.20 meters, as seen in Figure 14. It was found that 99.5+% of nodes are within NOAA allowable uncertainty.Difference surface between H13239 (gray) and junctioning survey H13245 (purple)SupportFiles\H13239_H13245_junction_surface.pngDifference surface statistics between H13239 and H13245 (4 meter surface)SupportFiles\H13239_MB_4m_MLLW_H13245_MB_4m_MLLW_depth_delta.pngSonar 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.Sound Speed IssuesThroughout the survey area, small sound speed artifacts are visible primarily as "smiles" in the data, resulting in a slight raise in the surface where adjacent lines overlap. An example is shown in Figure 15. All data were examined to ensure that these artifacts do not exceed the NOAA allowable uncertainty. The hydrographer is confident that all data remain sufficient to supersede previous data.Example of an area with sound speed artifacts, the vertical difference between lines is as much as 0.34 meters (surface exaggerated 20x)SupportFiles\H13239_sound_speed_artifact2.pngWeatherStrong winds and considerable swells were experienced throughout the survey area, leading to excessive bubbles in the water column near the transducer. This resulted in occasional temporary losses in bottom detection across consecutive pings, or "blowouts" (Figure 16). All blowouts were assessed in CARIS Subset Editor, and artifacts in excess of the TVU were rejected (Figure 17). Example of area where blowouts are prevalent (surface has 10x vertical exaggeration)SupportFiles\H13239_blowout_area.pngExample of an artifact in excess of the TVU as viewed in CARIS Subset Editor (surface exaggerated 20x)SupportFiles\H13239_artifact_in_excess_of_TVU.pngCasts were conducted at a minimum of one every four hours during launch acquisition. Casts were conducted more frequently when there was a change in surface sound speed greater than two meters per second. All sound speed methods were used as detailed in the DAPR.All equipment and survey methods were used as detailed in the DAPR.HolidaysH13239 data were reviewed in CARIS HIPS and SIPS for holidays in accordance with Section 5.2.2.3 of the HSSD. Six holidays which meet the definition described in the HSSD for complete coverage were identified via HydrOffice QC Tools Holiday Finder tool. This tool automatically scans the surface for holidays and was run in conjunction with a visual inspection of the surface by the hydrographer. One holiday is a result of improper spacing between survey lines leading to a gap in coverage, as shown in Figure 18. The other holidays were caused by removing data from blowouts, as shown in Figures 19-23. The holidays were determined by the hydrographer to be in areas of relatively unchanging bathymetry, where it is highly unlikely for any hazards to navigation to exist. Holiday due to a gap in coverage between survey linesSupportFiles\H13239_holiday1.pngHoliday due to removing data from a blowoutSupportFiles\H13239_holiday2.pngHoliday due to removing data from a blowoutSupportFiles\H13239_holiday3.pngHoliday due to removing data from a blowoutSupportFiles\H13239_holiday4.pngHoliday due to removing data from a blowoutSupportFiles\H13239_holiday5.pngHoliday due to removing data from a blowoutSupportFiles\H13239_holiday6.pngNOAA Allowable UncertaintyThe surface was analyzed using the HydrOffice QC Tools Grid QA feature to determine compliance with specifications. Overall, 99.5+% of nodes within the surface meet NOAA Allowable Uncertainty standards for H13239. For a graphical representation of compliance with uncertainty standards, see Figure 24 below.H13239 allowable uncertainty statisticsSupportFiles\H13239_MB_VR_MLLW_final.QAv5.tvu_qc.pngDensityThe surface was analyzed using the HydrOffice QC Tools Grid QA feature to determine compliance with specifications. Density requirements for H13239 were achieved with at least 99.5% of surface nodes containing five or more soundings as required by HSSD Section 5.2.2.3. For a graphical representation of compliance with density standards, see Figure 25 below.H13239 data density statisticsSupportFiles\H13239_MB_VR_MLLW_final.QAv5.density.pngAll data reduction procedures conform to those detailed in the DAPR.All sounding systems were calibrated as detailed in the DAPR.Raw backscatter data were stored in the .all file for the Kongsberg systems. All backscatter were processed to GSF files, and a floating point mosaic per vessel was created by the field unit via Fledermaus FMGT 7.8.10. A relative backscatter calibration was performed by HSTB in order to bring the survey systems on each of the launches into alignment. The offsets between launch sonar systems identified were entered into the Processing Settings within FMGT to increase continuity in the backscatter imagery collected by each vessel. See Figure 26 for a table of the entered calibration values. Due to an artifact observed in the mosaic generated from all data collected at 300kHz, separate mosaics were generated for each vessel. See Figure 27 for a greyscale representation of the complete mosaics.Backscatter Calibration ValuesSupportFiles\H13239_backscatter_calibration_values.pngBackscatter MosaicSupportFiles\H13239_backscatter_mosaic.pngTeledyne CARISHIPS and SIPS11.1.3QPSFledermaus FMGT7.8.10NOAA Profile Version 2019H13239_MB_VR_MLLW_Final.csarCARIS VR Surface (CUBE)Variable Resolution0.137.2NOAA_VRComplete MBESH13239_MB_VR_MLLW.csarCARIS VR Surface (CUBE)Variable Resolution0.137.2NOAA_VRComplete MBESThe NOAA CUBE parameters defined in the HSSD were used for the creation of all CUBE surfaces for H13239. The surfaces have been reviewed where noisy data, or "fliers," are incorporated into the gridded solutions causing the surface to be shoaler or deeper than the true sea floor. Where these spurious soundings cause the gridded surface to vary from the reliably measured seabed by greater than the maximum allowable Total Vertical Uncertainty at that depth, the noisy data have been rejected by the hydrographer and the surface recomputed. Flier Finder, part of the QC Tools package within HydrOffice, was used to assist the search for spurious soundings following gross cleaning. Flier Finder was run iteratively until all remaining flagged fliers were deemed to be valid aspects of the surface.Data LogsData acquisition and processing notes are included in the acquisition and processing logs, and additional processing such as vertical control and sound speed application are noted in the H13239 Data Log spreadsheet. All data logs are submitted digitally in the Separates I folder.Per Section 5.1.2.3 of the 2014 Field Procedures Manual, no Horizontal and Vertical Control Report has been generated for H13239.Mean Lower Low WaterERS via ERTDMR320FA2019_ERTDM_NAD83-MLLW.csarERS methods were used as the final means of reducing H13239 to MLLW for submission.North American Datum 1983Projected UTM 3Vessel kinematic data were post-processed using Applanix POSPac processing software and RTX positioning methods described in the DAPR. Smoothed Best Estimate of Trajectory (SBET) and associated error (RMS) data were applied to all MBES data in CARIS HIPS and SIPS.During real-time acquisition, 2805, 2807, and 2808 received correctors from the Wide Area Augmentation System (WAAS) for increased accuracies similar to USCG DGPS stations. WAAS and SBETs were the sole methods of positioning for H13239 as no DGPS stations were available for realtime horizontal control.A comparison was performed between survey H13239 and ENC US4AK86M using CARIS HIPS and SIPS sounding and contour layers derived from the VR surface. The contours and soundings were overlaid on the charts to assess differences between the surveyed soundings and charted depths. ENCs were compared by visual inspection to a VR grid, as the chart contained only four soundings within the sheet limits of H13239. All data from H13239 should supersede charted data. In general, surveyed soundings agree with the majority of charted depths. A full discussion follows below.US4AK86M10000052017-12-272017-12-27No shoals or potentially hazardous features exist for this survey.No charted features exist for this survey.No uncharted 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 Aids to navigation (ATONs) exist for this survey.No Maritime Boundary Points were assigned for this survey.Three bottom samples were acquired for survey H13239. Due to the risk of utilizing the image grab sampler from the launches in the observed sea states while on project, the smaller, non-image recording bottom sampler was used for all samples. One bottom sample with the coordinates of 58.547635 N, 161.681390 W was attempted three times, but was unsuccessful, likely due to rocky substrate. All successful bottom samples were entered in the H13239 Final Feature File. See Figure 31 for a graphical overview of sample locations.H13239 bottom sample locationsSupportFiles\H13239_bottom_samples_with_backscatter.pngNo overhead features exist for this survey.No submarine features exist for this survey.No platforms exist for this survey.No ferry routes or terminals exist for this survey.Large rolling sand waves up to 6.5 meters proud of the surrounding seafloor are present 2.2 nautical miles west of Cape Peirce, 0.5 to 2.4 nautical miles south of Cape Peirce, and 1.8 nautical miles east of Cape Peirce, as shown in Figure 32. Caution is advised to mariners transiting in this area, as the heights and locations of these sand waves likely varies temporally. Highlighted areas of rolling sand wavesSupportFiles\H13239_sandwaves_abnormal_seafloor.pngNo present or planned construction or dredging exist within the survey limits.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 Specifications and Deliverables, 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 herein.CAPT Marc MoserChief of Party2019-09-17LT Steve MoultonField Operations Officer2019-09-17CST Samuel CandioChief Survey Technician2019-09-17HAST Joseph AllmanSheet Manager2019-09-17