OPR-R320-FA-19Vicinity of Cape Newenham, AlaskaBristol BayNOAA Ship Fairweather (S220)H132381Cape NewenhamAlaskaUnited States400002019CAPT Marc MoserNavigable Area2019-04-302019-06-092019-07-16Multibeam 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 in Bristol Bay, Alaska within the sub locality of Cape Newenham.58.721812162.41299358.617373162.070489H13238 sheet limits (in blue) overlaid onto Chart 16305SupportFiles\H13238_Sheet_Limits.PNG H13238 with redefined NALL due to marine mammal hauloutSupportFiles\H13238_ Sheet_Limits_Sea_Lion_Haulout.png H13238 Sheet Limits with additional coverageSupportFiles\H13238_Sheet_Limits_Additional_Coverage.PNGData 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. A significant haul-out of Steller sea lions was observed at the western extent of Cape Newenham, preventing the field party from collecting data within 0.5 nautical miles in accordance with guidance provided by the Marine Mammal Protection Act (Figure 2). These individuals are members of the endangered western distinct population segment, of which human disturbance is listed as a primary potential threat. Extra considerations were taken in this area to prevent stress to individuals present on the haul-out, and to avoid potential flushing. Following the completion of survey operations on the assigned sheets within the project area, guidance was received from HSD to continue acquisition northward with the remaining time, utilizing 400 meter set line spacing. A record of this correspondence is located in Appendix II of this report.The purpose of this hydrographic survey is to update National Ocean Service nautical charting products and support commerce to the northern Bristol Bay region. Cape Newenham is in the southwestern corner of Togiak National Wildlife Refuge and provides 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 Stait must transit around these capes. Marine commerce is critical for the survival of these western Alaskan communities as they are detached form the rest of the state road system. Legacy hydrographic data in this survey is extremely sparse and was acquired prior to the 1920s. Updating 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 H13238 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 Sheet H13238Complete Coverage Following initial acquisition on the offshore portion of H13238, it was determined that little bathymetric variation was likely to exist and that the area could be adequately addressed via 400 meter set line spacing. A request to relax the complete coverage requirement to set line spacing was granted by the Project Manager following the analysis by the field unit. See Figure 4 for an overview of the survey coverage. See Appendix II for a record of this correspondence.H13238 survey coverage overlaid onto chart 16305SupportFiles\H13238_Coverage_Overview.png2805083.88000006.7402806048.3100000002807075.86000009.5602808069.960000000S2200239.100000018.3700517.110000034.706.7500047.292019-06-092019-06-102019-06-112019-06-122019-06-132019-06-192019-06-202019-06-222019-06-282019-07-102019-07-16Refer to the OPR-R320-FA-19 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.S22070.44.828058.61.128068.61.128078.61.128088.61.1Kongsberg MaritimeEM 710MBESKongsberg MaritimeEM 2040MBESSea-Bird ScientificSBE 19plus V2Conductivity, Temperature, and Depth SensorAML OceanographicMVP200Conductivity, Temperature, and Depth SensorTeledyne RESONSVP 70Sound Speed SystemTeledyne RESONSVP 71Sound Speed SystemApplanixPOS MV 320 v5Positioning and Attitude SystemThe equipment was installed on the survey platforms as follows: All MBES survey vessels are equipped with POS MV v5 systems for positioning and attitude. S220 utilizes the Kongsberg EM 710 MBES, SVP 70 surface sound speed sensors, and AML Oceanographic MVP 200 for conductivity, temperature, and depth (CTD) casts. All launches utilize Kongsberg EM 2040 MBES, 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. Additional crossline data were collected across the area addressed by set line spacing data to ensure that the crossline percentage in this area exceeded 8% as required by 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 (Crosslines - Mainscheme = difference surface) was generated (Figure 5), 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 0.00m with 95% of nodes falling within +/- 0.17m (Figure 6). For the respective depths, the difference surface was compared to the allowable NOAA uncertainty standards. In total 99.8% of the depth differences between H13238 mainscheme and crossline data were within allowable NOAA uncertainties. Overview of H13238 CrosslinesSupportFiles\H13238_Crossline_Comparison.pngH13238 crossline and mainscheme difference statisticSupportFiles\H13238_Mainscheme_Surface-H13238_Crossline_Surface_depth_delta.pngERS via ERTDM00.14280x (All Launches)2 N/A 0.5S220N/A1 0.5In addition to the usual a priori estimates of uncertainty provided via device models for vessel motion and the Ellipsoidally Referenced Tidal Datum Model (ERTDM), real-time and post-processed uncertainty sources were also incorporated into the depth estimates of survey H13238. Real-time uncertainties were provided via EM 710 and 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 files generated in Applanix POSPac.H13238 junctions with five adjacent surveys from this project, H13245, H13239, H13240, H13241, and H13242 as shown in Figure 7. Data overlap between H13238 and each adjacent survey was achieved. These areas of overlap between surveys were reviewed in 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 H13238 are generally within the NOAA allowable uncertainty in their areas of overlap. For all junctions with H13238, a negative difference indicates H13238 was shoaler, and a positive difference indicates H13238 was deeper. Overview of H13238 junction surveysSupportFiles\Junctions.pngH13245400002019NOAA Ship FAIRWEATHERSESurface differencing in CARIS HIPS and SIPS was used to assess junction agreement between the surface from H13238 and the surface from H13245. The statistical analysis of the difference surface shows a mean of - 0.04 meters with 95% of all nodes having a maximum deviation of +/- 0.24 meters. It was found that 99% of all nodes are within NOAA allowable uncertainty. Difference surface between H13238 (blue) and junctioning survey H13245 (pink)SupportFiles\H13238-H13245 Junction.PNGFigure 9. Difference surface statistics between H13238 and H13245SupportFiles\H13238_MB_4m_MLLW-H13245_MB_4m_MLLW_1_depth_delta.pngH13239400002019NOAA Ship FAIRWEATHERSSurface differencing in CARIS HIPS and SIPS was used to assess junction agreement between the surface from H13238 and the surface from H13239. The statistical analysis of the difference surface shows a mean of 0.01 meters with 95% of all nodes having a maximum deviation of +/-0.14 meters. It was found that 99.5% of all nodes are within NOAA allowable uncertainty. Difference surface between H13238 (Blue) and junctioning survey H13239 (Brown)SupportFiles\H13238-H132239 Junction.PNGDifference surface statistics between H13238 and H13239SupportFiles\H13238-H13239 Junction Statistics_depth_delta.pngH13240400002019NOAA Ship FAIRWEATHERSSurface differencing in CARIS HIPS and SIPS was used to assess junction agreement between the surface from H13238 and the surface from H13240. The statistical analysis of the difference surface shows a mean of 0.13 meters with 95% of all nodes having a maximum deviation of +/-0.18 meters. It was found that 100% of all nodes are within NOAA allowable uncertainty.Difference surface between H13238 (dark blue)and H133240 (light blue)SupportFiles\H13238_H13240 Junction.PNGDifference surface statistics between H13238 and H13240SupportFiles\H13238_MB_4m_MLLW-H13240_MB_4m_MLLW_depth_delta.pngH13241400002019NOAA Ship FAIRWEATHERSSurface differencing in CARIS HIPS and SIPS was used to assess junction agreement between the surface from H13238 and the surface from H13241. The statistical analysis of the difference surface shows a mean of 0.00 meters with 95% of all nodes having a maximum deviation of +/-0.09 meters. It was found that 100% of all nodes are within NOAA allowable uncertainty.Difference surface between H132338 (blue) and H13241 (purple)SupportFiles\H13238-H13241 Junction.PNGDifference surface statistics between H13238 and H13241SupportFiles\H13238_MB_4m_MLLW-H13241_MB_4m_MLLW_Final_depth_delta.pngH13242400002019NOAA Ship FAIRWEATHERWSurfacing difference in CARIS HIPS and SIPS was used to assess junction agreement between the surface from H13238 and H13242. The statistical analysis of the difference surface shows a mean of 0.00 meters with 95% of nodes having a maximum deviation of +/-0.09 meters. It was found that 100% of all nodes are within NOAA allowable uncertainty.Difference surface between H13238 and H13242SupportFiles\H13238-H13242 Junction.PNGDifference surface statistics between H13238 and H13242SupportFiles\H13238_MB_4m_SLS_MLLW-H13242_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 IssuesIn certain areas, particularly west of the sand waves in the northeast portion of the sheet limits, small sound speed issues were apparent and visible primarily as "smiles". Surfaces were not significantly impacted and the data meet NOAA allowable uncertainty standards. As such, the data remain sufficient to supersede previous soundings.H13238 Issues with sound speedSupportFiles\VR_Surface_overlaid_on_Chart.pngCTD casts were conducted at a minimum of once every four hours during launch acquisition. Casts were conducted more frequently in areas where the influx of freshwater had an effect on the speed of sound in the water column and when there was a change in surface sound speed greater than two meters per second. MVP casts on S220 were conducted at an average interval of 30-45 minutes, guided by observation of the surface sound speed and targeted to deeper areas. All sound speed methods were used as detailed in the DAPR.All equipment and survey methods were used as detailed in the DAPR.HolidaysH13238 data were reviewed in CARIS HIPS and SIPS for holidays in accordance with Section 5.2.2.3 of the HSSD. Three holidays which meet the 3 by 3 node definition were identified via HydrOffice QC Tools Holiday Finder tool. This tool automatically scans the surface for holidays as defined in the HSSD and was run in conjunction with a visual inspection of the surface by the hydrographer. Reasonable attempts were made to ensure full coverage of the area but these areas were not able to be acquired due to time constraints. All holidays are the result of insufficient overlap between lines, as shown in Figure 19. Depiction of holidays in H13238. SupportFiles\H13238_Holidays.pngNOAA Allowable UncertaintyThe variable resolution surface and 4 meter single resolution surface were both analyzed using the HydrOffice QC Tools Grid QA feature to determine compliance with specifications. Overall 99.5+ % of nodes within each surface meet NOAA Allowable Uncertainty specifications for H13238. For the individual graph per surface of density requirements, see Figures 20 and 21 below.H13238 Allowable Uncertainty Statistics for Variable Resolution SurfaceSupportFiles\H13238_MB_VR_MLLW_Final.QAv5.tvu_qc.pngH13238 Allowable Uncertainty Statistics for 4 meter SurfaceSupportFiles\H13238_MB_4m_MLLW_Final.QAv5.tvu_qc.pngDensityThe variable resolution surface and the 4 meter single resolution surface were both analyzed using the HydrOffice QC Tools Grid QA feature and the results are shown in Figures 22 and 23 below. Density requirements for H13238 were achieved with at least 99.5+% of the nodes for each surface containing five or more soundings as required by HSSD Section 5.2.2.3 H13238 Data Density Statistics for Variable Resolution SurfaceSupportFiles\H13238_MB_VR_MLLW_Final.QAv5.density.pngH13238 Data Density Statistics for 4 meter SurfaceSupportFiles\H13238_MB_4m_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 all 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 via a patch test in order to bring the survey systems on each of the launches into alignment. The offsets between launch sonar systems identified by the patch test were entered into the Processing Settings within FMGT to increase continuity in the backscatter imagery collected by each vessel. See Figure 24 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 25 for a greyscale representation of the complete mosaics. Backscatter Calibration ValuesSupportFiles\Backscatter_Calibration_Table.png Overview of H13238 backscatter mosaicsSupportFiles\H13238_Backscatter.PNGTeledyne CARISHIPS and SIPS11.1.3QPSFledermaus FMGT7.8.10NOAA Profile Version 2019H13238_MB_VR_MLLW_FinalCARIS VR Surface (CUBE)Variable Resolution1.849.2NOAA_VRComplete MBESH13238_MB_4m_MLLW_FinalCARIS Raster Surface (CUBE)425.849.2NOAA_4mMBES Set Line SpacingH13238_MB_VR_MLLWCARIS VR Surface (CUBE)Variable Resolution1.849.2NOAA_VRComplete MBESH13238_MB_4m_MLLWCARIS Raster Surface (CUBE)425.849.2NOAA_4mMBES Set Line SpacingThe NOAA CUBE parameters defined in the HSSD were used for the creation of all CUBE surfaces for H13238. 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 be shoaler or deeper than 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 sea floor.Data LogsData Acquisition and processing notes are included in the acquisition and processing logs, and additional processing such as sound speed application are noted in the H13238 Data Log spreadsheet. All data logs are submitted digitally in the Separates I folderPer section 5.1.2.3 of the 2014 Field Procedures Manual, no Horizontal and Vertical Control Report has been generated for H13238.Mean Lower Low WaterERS via ERTDMR320FA2019_ERTDM_NAD83-MLLW.csarERS methods were used as the final means of reducing H13238 to MLLW for submissionNorth American Datum 1983Projected UTM 3RTXVessel kinematic data were post-processed using Applanix POSPac processing software and RTX positioning methods described in the DAPR. Smoothed Best Estimate Trajectory (SBET) and associated error (RMS) data were applied to all MBES data in CARIS HIPS and SIPS.During real time acquisition, all platforms 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 H13238 as no DGPS stations were available for realtime horizontal control.A comparison was performed between survey H13238 and ENC US4AK86M using CARIS HIPS and SIPS sounding and contours layers derived from the full coverage VR surface and the 4 meter surface used for set line spacing. The contours and soundings were overlaid on the charts to visually assess differences between the surveyed soundings and charted depths. In general, surveyed soundings agree with the majority of charted depths. All data from H13238 should supersede charted data.US4AK86M10000052017-12-272017-12-27falseSoundings from H13238 are in general agreement with charted depths on chart US4AK86M with most depths agreeing to two fathoms as shown in Figure 26. The greatest differences in depth are up to six fathoms in two localized areas shown in the image below. Contours from H13238 are in general agreement with the 10 fathom contour but deviate significantly from the 20 fathom contour on chart US4AK86M as shown in Figure 27 . The greatest differences are seen in the north side of the sheet limits where new coverage was acquired using set line spacing. Comparison of H13238 soundings (pink) as compared to chart US4AK86M depths (black)SupportFiles\ENC with soundings comparison_2.PNGComparison of H13238 Contours (black) compared to those on chart US4AK86MSupportFiles\ENC with contour comparison.pngNo Maritime Boundary Points were assigned for this survey.No charted features exist for this survey.No uncharted features exist 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.Five bottom samples were acquired for survey H13238. 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 five samples. All bottom samples were entered in the H13238 Final Feature File. See Figure 28 for a graphical overview of sample locations.H13238 bottom sample locations overlaid on backscatter mosaicSupportFiles\Bottom Sample Locations.PNGH13238 survey limits extended to the NALL (see Section A.1) and features within these limits were addressed and attributed in the H13238 Final Feature File. All features inshore of NALL were attributed in the Final Feature File with the description of "Not Addressed" and remarks of "Retain as charted, not investigated due to being inshore of the NALL" as per the HSSD Section 7.3.1. Annotations and information collected on boat sheets during field operations are scanned and included in the Separates I Detached Positions folder.No Aids to navigation (ATONs) exist for this survey.No 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.The sea floor for the majority of H13238 was relatively flat; however, there was one particular area in the northeast corner of the project area where sand waves were observed to reach as high as three meters. Significant currents and tide rips were observed in this same area. Caution is advised to mariners transiting in this area, as the heights and locations of these sand waves likely varies temporally. Sand Waves in NE corner of H13238SupportFiles\H13238_Sand_Waves.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 in the Descriptive Report.