OPR-P377-RA-17Cold BayCold Bay, AKNOAA Ship RAINIERH130318East Of Deer IslandAlaskaUnited States400002017Benjamin K. Evans, CDR/NOAANavigable Area2017-06-072017-08-222017-08-29Multibeam Echo Sounder /Lead LineMultibeam Echo Sounder BackscattermetersUniversal Transverse Mercator (UTM)UTCPacific Hydrographic BranchThe purpose of this survey is to provide contemporary surveys to update National Ocean Service (NOS) nautical charts. All separates are filed with the hydrographic data. Any revisions to the Descriptive Report (DR) generated during office processing are shown in bold red italic text. The processing branch maintains the DR as a field unit product, therefore, all information and recommendations within the body of the DR are considered preliminary unless otherwise noted. The final disposition of surveyed features is represented in the OCS nautical chart update products. All pertinent records for this survey, including the DR, are archived at the National Centers for Environmental Information (NCEI) and can be retrieved via http://www.ncei.noaa.gov/NOAAThe survey area is referred to as "East of Deer Island" (sheet 8) in the Project Instructions. The area encompasses approximately 33 square nautical miles from the northern portion of Deer Island, Stag Point, to the western shores of the same island and about 1.3 nautical miles north of Patton Island.55.0125888889162.30229722254.9175388889162.045755556Data were acquired within survey limits as required in the Project Instructions and HSSD unless otherwise noted in this report.H13031 Assigned Survey Area.SupportFiles\Sheet limits Area for DR.PNGThis navigationally significant area from Unga Strait to the northeast and the north side of Sanak Island to the southwest provides the only protected waters for vessels transiting between areas to the east in the Gulf of Alaska and Shelikof Strait and Unimak Passage, which is the gateway to the Bering Strait utilized by cargo, fishing, and trans-pacific vessels. Deer Passage is specifically utilized by the fishing fleet in Bristol Bay and the Bering Sea and the tug and tow traffic delivering goods to the Aleutian Islands, western Alaska, and the Arctic. This project area was last surveyed between 1911 and 1941. Survey data from this project is intended to supersede all prior survey data in the common area and update nautical charts with modern data to support safe navigation.The entire survey is adequate to supersede previous data.Pydro QC Tools 2 "Grid QA" was used to analyze H13031 multibeam echosounder (MBES) data density. The submitted H13031 variable-resolution (VR) surface met HSSD density requirements.Pydro derived histogram plot showing HSSD density compliance of H13031 finalized variable-resolution MBES data.SupportFiles\H13031_MB_VR_MLLW_Final.QAv5.density.pngAll waters in survey area.Complete Coverage (refer to HSSD Section 5.2.2.3).Complete multibeam echosounder (MBES) coverage was acquired to the inshore limit of hydrography, the Navigable Area Limit Line (NALL). Four gaps in coverage (holidays), in the southeastern survey area, are due to the presence of underwater rocks resulting in hazardous conditions for acquisition (Figure 4). Least depths were acquired for these areas by use of lead-line and denoted in the H13031 Final Feature File (FFF). All other survey data met the 4-meter depth contour specified by the definition of the NALL except for few specific areas along the shoreline. Two acoustic shadows are present in the eastern survey data caused by seafloor topography (Figure 5).Example of H13031 NALL Determination; Yellow indicating where the 4-meter curve has been met and Red indicates areas shallower than 4-meters.SupportFiles\NALL Limit for DR.PNGH13031 holidays in survey data caused by uncharted underwater rocks in a relatively shallow area. SupportFiles\HolidaysDR.PNGAcoustic shadows present in H13031 survey data.SupportFiles\Acoustic_Shadows_DR.PNGConcur with clarification, there are three holidays caused by underwater rocks located in the SW corner of the survey. The coverage gap located over a charted 6 fathom in the SE corner of the survey is due to an acoustic shadow. No signs of shoaling in the vicinty of the gap was found during office review. H13031 MBES Coverage and Assigned Sheet Limits (Chart 16549).SupportFiles\H13031 Survey Area for DR.PNGS2210171.49000000028010103.070000022.82028020107.07000000028040139.490000018.2100521.1500000007.876022032.642017-08-222017-08-232017-08-242017-08-252017-08-262017-08-272017-08-282017-08-292017-08-30Refer 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.28018.81.128028.81.128048.81.1S22170.44.719055.70.37NOAA Ship RAINIER alongside Kodiak Coast Guard Base, Kodiak, AK with survey launches. SupportFiles\Rainier for DR.PNGThe NOAA Ship RAINIER and the survey launches, RA-4, RA-5, and RA-6, collected multibeam data on sheet H13031. RAINIER's survey skiff, RA-8, was used for collecting shoreline data at the start of acquisition. Shoreline data collection was completed on the first day of acquisition, August 22, 2017. Lead-line was used to determine least depths on a number of features on August 28.ResonSeaBat 7125 SV2MBESResonSeaBat 7125-BMBESResonSVP71, SVP70Surface Sound Speed SensorApplanixPOS MV v5Positioning and Attitude SystemKongsbergEM 710MBESSea-Bird ElectronicsSBE 19plus SeaCat ProfilerConductivity, Temperature, and Depth SensorODIM Brooke OceanMVP200 Moving Vessel ProfilerSound Speed SystemMultibeam crosslines were acquired using RAINIER launches 2801 and 2804 across most depth ranges with good spatial distribution throughout the survey area; they are adequate for verifying and evaluating the internal consistancy of survey data. A 4-meter CUBE surface was created using H13031 mainscheme and crossline data and a second 4-meter surface was created using only crosslines. Statistics were derived using the Pydro "Compare Grids" tool using both 4-meter surfaces. For its respective depths, the difference surface was compared to IHO allowable Total Vertical Uncertainty (TVU) standards. In total, 99.5+% of the depth differences between H13031 mainscheme and crossline data met HSSD TVU standards. The analysis was performed on H13031 MBES data reduced to Mean Lower-Low Water (MLLW) using Ellipsoidally Referenced Zoned Tides (ERZT) methods. A 4-meter CUBE surface was used for this crossline analysis; this is due to Pydro's "Compare Grids" tool not having the ability to compare variable resolution grids.Graph indicating percentage of difference surface nodes between H13031 mainscheme and crossline data that met HSSD allowable TVU standards. SupportFiles\H13031_MB_4m_MLLW-H13031_MB_4m_MLLW_XL_fracAllowErr_Freq.pngPydro derived plot showing the One Standard deviation of H13031 mainscheme to crossline data.SupportFiles\H13031_MB_4m_MLLW-H13031_MB_4m_MLLW_XL_depth_delta.pngH13031 crossline surface overlaid on mainscheme tracklines showing good temporal and geographic distribution. SupportFiles\Crosslines for DR.PNG00.0265ERS via ERZT2801, 2802, 280430.15S22110.05Total Propagated Uncertainty (TPU) values for survey H13031 were derived from a combination of fixed values for equipment and vessel characteristics, as well as from field assigned values for sound speed uncertainties. Tidal uncertainty was accounted for by examining the field generated one thousand-meter resolution separation model and statistically determining a measured value. A measured uncertainty of 0.0265 meters was entered to account for ERZT processing methods. See the 2017 DAPR for further information. In addition to the usual a priori estimates of uncertainty, some real-time and post-processed uncertainty sources were also incorporated into the depth estimates of this survey. Real-time uncertainties from Reson MBES sonars were recorded and applied during post-processing. Applanix TrueHeave (POS) files, which record estimates of heave uncertainty, were also applied during post-processing. Finally, the post-processed uncertainties associated with vessel roll, pitch, yaw and position were applied in Caris HIPS using SBET / RMS files generated using POSPac software. Pydro tool "QC tools 2" were used to analyze H13031 TVU compliance; a histogram plot of the results is shown below. Histogram plot, produced by the Pydro QC tools 2 program, showing TVU compliance of H13031 finalized variable-resolution MBES data.SupportFiles\H13031_MB_VR_MLLW_Final.QAv5.tvu_qc.pngFour surveys junction with H13031, two are contemporary and part of project OPR-P377-RA-17_Cold_Bay_&_Vicinity. The other two surveys were conducted by NOAA Ship RAINIER in 2008.H13031 junction surveys.SupportFiles\H13031 Junctions.PNGH13027400002017NOAA Ship RAINIERWThe junction with survey H13027 encompassed 0.08 square nautical miles along the western boundary of H13031. The comparison was made using the Pydro tool "Compare Grids" application. The surfaces used for this comparison were 4-meter CUBE surfaces. Analysis of the difference surface indicated that H13031 is an average of 0.025 meters shallower than H13027 with a standard deviation of 0.142 meters. For the respective depths, the difference surface was compared to the allowable TVU standards specified in the HSSD. In total, 99.5+% of the depth differences between H13031 and junction survey H13027 were within allowable uncertainties.Junction between surveys H13031 and H13027.SupportFiles\H13031-H13027 Junction.PNGHistogram plot utilizing the magnitude of the Allowable Error Fraction indicastes that 99.5+% of the nodes pass TVU compliance.SupportFiles\H13031_MB_4m_MLLW-H13027_MB_4m_MLLW_fracAllowErr_Freq.pngA depth-dependent plot detailing the Allowable Error Fraction, where values between-and- including +/- 1 represent "passing comparisons" for the H13031 and H13027 junction analysis.SupportFiles\H13031_MB_4m_MLLW-H13027_MB_4m_MLLW_fracAllowErr_vsDepth.pngH13024400002017NOAA Ship RAINIERNThe junction with survey H13024 encompassed 1.26 square nautical miles along the northern boundary of H13031. The comparison was made using the Pydro tool "Compare Grids" application. The surfaces used for this comparison were 4-meter CUBE surfaces. Analysis of the difference surface indicated that H13031 is an average of 0.067 meters shallower than H13024 with a standard deviation of 0.196 meters. For the respective depths, the difference surface was compared to the allowable TVU standards specified in the HSSD. In total, 99.5+% of the depth differences between H13031 and junction survey H13027 were within allowable uncertainties.Junction between H13031 and H13024.SupportFiles\H13031-H13024 Junction.PNGHistogram plot utilizing the magnitude of the Allowable Error Fraction indicates that 99.5+% of the nodes pass TVU compliance.SupportFiles\H13031_MB_4m_MLLW-H13024_MB_4m_MLLW_fracAllowErr_Freq.png A depth-dependent plot detailing the Allowable Error Fraction, where values between-and- including +/- 1 represent "passing comparisons" for the H13031 and H13024 junction analysis.SupportFiles\H13031_MB_4m_MLLW-H13024_MB_4m_MLLW_fracAllowErr_vsDepth.pngH11904100002008NOAA Ship RAINIERNEThe junction with survey H11904 encompassed 0.33 square nautical miles along the northeastern boundary of H13031. The comparison was made using the Pydro tool "Compare Grids" application. The surfaces used for this comparison were 4-meter CUBE surfaces. Analysis of the difference surface indicated that H13031 is an average of 0.119 meters shallower than H13024 with a standard deviation of 0.091 meters. For the respective depths, the difference surface was compared to the allowable TVU standards specified in the HSSD. In total, 99.5+% of the depth differences between H13031 and junction survey H11904 were within allowable uncertainties.Junction between H13031 and H11904.SupportFiles\H13031-H11904 junction.PNGHistogram plot utilizing the magnitude of the Allowable Error Fraction indicates that 99.5+% of the nodes pass TVU compliance.SupportFiles\H13031_MB_4m_MLLW-H11904_4m_Combined_MLLW_4of4_fracAllowErr_Freq.png A depth-dependent plot detailing the Allowable Error Fraction, where values between-and- including +/- 0.5 represent "passing comparisons" for the H13031 and H11904 junction analysis.SupportFiles\H13031_MB_4m_MLLW-H11904_4m_Combined_MLLW_4of4_fracAllowErr_vsDepth.pngH11932200002008NOAA Ship RAINIEREThe junction with survey H11932 encompassed 0.36 square nautical miles along the eastern boundary of H13031. The comparison was made using the Pydro tool "Compare Grids" application. The surfaces used for this comparison were 4-meter CUBE surfaces. Analysis of the difference surface indicated that H13031 is an average of 0 meters shallower than H11932 with a standard deviation of 0.440 meters. For the respective depths, the difference surface was compared to the allowable TVU standards specified in the HSSD. In total, 97% of the depth differences between H13031 and junction survey H11932 were within allowable uncertainties.Junction between H13031 and H11932.SupportFiles\H13031-H11932 Junction.PNGHistogram plot utilizing the magnitude of the Allowable Error Fraction indicates that 97% of the nodes pass TVU compliance.SupportFiles\H13031_MB_4m_MLLW-H11932_MB_4m_MLLW_combined_fracAllowErr_Freq.png A depth-dependent plot detailing the Allowable Error Fraction, where values between-and- including +/- 1 represent "passing comparisons" for the H13031 and H11932 junction analysis.SupportFiles\H13031_MB_4m_MLLW-H11932_MB_4m_MLLW_combined_fracAllowErr_vsDepth.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.Sea State Effects During AcquisitionIn some offshore areas of H13031 as well as areas closer to shore, sea state affected bottom detection and data quality. Swell and wind speed caused excessive blow-outs during acquisition introducing soundings not reflecting the seafloor into the data. Areas where soundings caused by noise could be distinguished from the apparent seafloor, soundings were rejected. In areas where the seafloor and noise could not be distinguished, no soundings were rejected. The image depicted below is of the finalized variable resolution surface with a verticle exaggeration of 7. Example of sea state effects on data acquired on DN236.SupportFiles\Sea-State_DR.PNGThe cast frequency for survey H13031 complies with the Office of Coast Survey Field Procedures Manual. Casts were taken once every four hours or where a two meter per second difference in sound speed were apparent. Total casts amounted to 69 sound velocity profiles. During ship acquisition, the Moving Vessel Profiler was deployed, on average, once every hour. Casts were taken in deep water when safe to deploy the Conductivity, Temperature, Density (CTD) device. The sea state varied during acquisition making Sound Velocity casts difficult to conduct at times. All data were processed using "Nearest in Distance within Time" (4 hours) except crosslines XL_2801_2017_2391726, XL_2801_2017_2391827, and XL_2804_2017_2391918 which were processed with Nearest in Time in order to apply more appropriate sound velocity profiles. One sound velocity cast was deleted, MVP_2017-08-26_204000, from the master concatenated file due to relatively shallow depth. The data were sound velocity corrected afterwards. Two casts lie outside the sheet limits for survey H13031; these were test casts conducted by the ship's MVP device before acquisition and deemed applicable to the survey.H13031 Sound Speed Cast Locations.SupportFiles\Sound Speed Casts for DR.PNGAll equipment and survey methods were used as detailed in the DAPR.Pydro QC Tools 2 "Flier Finder"Pydro QC Tools 2 "Flier Finder" was user to further analyze H13031 survey data. The application determined zero fliers present in the most recent finalized variable resolution surface. However, few fliers were found in previous verisons of the finalized surface. There are no results to include with this report. All data reduction procedures conform to those detailed in the DAPR.All sounding systems were calibrated as detailed in the DAPR.Raw Backscatter was logged as 7k and .all files and has been sent to the Processing Branch. Backscatter was processed by the field unit. One 2-meter resolution mosaic was created for each vessel and frequency for sheet H13031. Fledermaus Geocoder Toolbox, "FMGT" a product of QPS, was used to process backscatter and produce backscatter mosiacs. The product version used is 7.7.8. Errors were encountered during processing; a "Auto Time-Sync Algorithm Failure" error occured while pairing the .7k and HDCS data. This is due to an offset between GPS time and UTC time being misapplied due to a version conflict between Caris and FMGT. Troubleshooting efforts between the field unit and HSTB resulted in the solution of adding a -2.0 second merge offset, which was applied to merge the data sets and produce backscatter mosaics. An email from HSTB and the field unit RAINIER is located in the Correspondence folder of this report.CarisHIPS/SIPS10.2, 10.3.1, 10.3.3QPSFledermaus Geocoder Toolbox7.7.8NOAA Profile V_5_6H13031_MB_VR_MLLWCARIS VR Surface (CUBE)Variable Resolution1.2120.5NOAA_VRComplete MBESH13031_MB_VR_MLLW_FinalCARIS VR Surface (CUBE)Variable Resolution1.2120.5NOAA_VRComplete MBESSubmitted surfaces were generated using the recommended parameters for "Ranges" based variable resolution bathymetric grids as specified in HTD2017-2. No soundings have been designated for sheet H13031 and no DTONs were detected throughout the survey area. Shoreline features were reduced to MLLW using traditional tide methods via TCARI. All MBES bathymetry were acquired relative to the ellipsoid and reduced to MLLW via ERZT. Additional information discussing the vertical or horizontal control for this survey can be found in the accompanying HVCR.Mean Lower Low WaterKing Cove, Alaska9459881TCARIH13031_Feature_Tides.tidFinal ApprovedP377RA2017.tcFinal2017-09-072017-09-15H13031 shoreline features were tide corrected using a .tid file created in Pydro utilizing the "TCARI TID file via S-57" function then loaded in Caris 10.3. H13031 MBES data were reduced to MLLW using ERZT processing methods. ERS via ERZTH13031_1000m_SeparationModel_Final.csarEllipsoidally Referenced Zoned Tides (ERZT) methods were used to transform between the ellipsoid and water level data. A 1000-meter resolution separation model was computed between the ellipsoid and MLLW using real-time position measurements observed during the survey relative to the vessel water line and the TCARI tide file. "GPS tides" were then computed using the above separation model and the corrected GPS height-to-water-level data (SBET). The 1000-meter resolution separation model was generated in NAD83 as were the SBETs. Refer to the 2017 DAPR for additional information.North American Datum of 1983 (NAD83)Univeral Transverse Mercator (UTM) Zone 3Single Base9715FoxyThe Wide Area Augmentation System (WAAS) was used for real-time horizontal control for this survey.A comparison was made between H13031 survey data and Electronic Navigation Chart (ENC) US4AK55M using CUBE surfaces and contours created in Caris. US4AK55M80000212017-12-152017-12-15falseA comparison was made between H13031 surveyed contours and ENC US4AK55M with the following results: H13031 3-fathom surveyed contour generally agree with the charted 3-fathom depth curve except for the southern areas where ledges and foul ground are present. The 3-fathom surveyed contour line lies further offshore than the charted 3-fathom depth curve in these areas, on average of about 100 meters (Figure 27). Also, 3-fathom surveyed contours are present about 50 meters inshore of the charted 5-fathom depth curve in the southern portion of the survey area. An underwater rock is present on the eastern limits of the survey area and shows a positional offset when compared to the charted contours of the ENC chart. Revision is required in these areas. H13031 5-fathom surveyed contour generally agrees with the charted 5-fathom depth curve. Some discontinuities persist in the southeastern survey area where ledges and foul ground are present (Figure 28). Also, there are surveyed contours that lie offshore of the charted depth curve with the average distance being about 100 meters. Revision is required in these areas. H13031 10-fathom surveyed contour agrees more so with the charted 10-fathom depth curve throughout the sheet. There is one contour line that is misrepresented when compared to the H13031 surveyed contour. There are some areas where the derived contour line lies offshore of the charted 10-fathom depth curve with an average distance of about 60 meters (Figure 29). Revision may be required in these areas. H13031 20-fathom surveyed contours, when compared to the charted 20-fathom depth curve, shows little discontinuity, although few positional offsets are present. The offshore underwater rock located in the eastern survey area shows the charted 20-fathom depth curve as smaller than charted with the contours being, on average, 100 meters inside the charted 20-fathom depth curve. There are a few shoal areas offshore of the charted depth curve showing an offset of about 150 meters (Figure 30). Little revision is required for these areas. H13031 30-fathom surveyed contours follows the same general trend as the charted 30-fathom depth curve, however multiple positional offsets are present. About three kilometers east of Stag Point, northern Deer Island, shows discontinuity between the charted depth curve and H13031 surveyed contours. The shoals located between the charted 30 and 50-fathom surveyed contours also show positional offsets on average of about 100 meters. A shoal between the 30 and 50-fathom depth curves that was not previously charted is also present in the northern survey area, about 6.5 kilometers east of Stag Point (Figure 31). Revision is required for these areas. H13031 50-fathom surveyed contours agree with the charted 50-fathom depth curve with little discrepancies. There are few deeper areas between the charted 30 and 50-fathom depth curves that are consistent with scours on the seaward edge of deep underwater features. The northwestern survey area shows one consistently deep area where the charted 50-fathom depth curves are separated by shoaler areas (Figure 32). Little revision is required for these areas. ENC US4AK55M overlaid with H13031 3 fathom surveyed contour.SupportFiles\3fathomsDR.PNGENC US4AK55m overlaid with H13031 5 fathom surveyed contour.SupportFiles\5fathomDR.PNGENC US4AK55m overlaid with H13031 10 fathom surveyed contour.SupportFiles\10fathomDR.PNGENC US4AK55m overlaid with H13031 20 fathom surveyed contour showing positional offsets.SupportFiles\20fathomDR.PNGENC US4AK55m overlaid with H13031 30 fathom surveyed contour showing positional offsets.SupportFiles\30fathomDR.PNGENC US4AK55m overlaid with H13031 50 fathom surveyed contourSupportFiles\50fathomDR.PNGNo Maritime Boundary Points were assigned for this survey. All charted features that were assigned to the field unit, provided by the Composite Source File, were investigated and properly attributed in the H13031 Final Feature File.No new navigationally significant features were detected that were not included in the H13031 Final Feature File or elsewhere in this report.Features of navigational significance are discussed in the chart comparison sections above or are included in the H13031 Final Feature File submitted with this report.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.Three bottom samples were acquired for this survey; the results are included in the H13031 Final Feature File submitted with this report. Six bottom samples were assigned but only three samples were successfully acquired after attempting to acquire three times. The three failed bottom sample sites are included with the H13031 Final Feature File. Limited shoreline verification was conducted in accordance with applicable sections of NOAA HSSD and FPM using the Project Reference File (PRF) and Composite Source File (CSF) provided with the Project Instructions. In the field, all assigned features that were safe to approach, were addressed as required with S-57 attribution and recorded in the H13031_Final_Feature_File (FFF) to best represent the features at chart scale. This file also includes new features found in the field as well as recommendations to update, retain or delete assigned featuresNo prior survey comparisons exist for this survey.The project instructions for this survey did not assign Aids to Navigation, however, a lighted daymark was assigned in the Composite Source File and incorporated into the H13031 FFF. The daymark and light (Number 27180) lies about 90 meters outside the assigned sheet limits at the head of Stag Point on the northern point of Deer Island and appeared to be serving its intended purpose. This feature was addressed as required with S-57 attribution and recorded in the H13031_Final_Feature_File (FFF) to best represent the feature at chart scale. Daymark and light 27180.SupportFiles\RA-8_DN234_P1040356.JPGNo overhead features exist for this survey.A charted cable area is present crossing the northen portion of the H13031 survey area. No evidence of cables was found in the MBES data.Raster chart showing Cable AreaSupportFiles\Cable_Area_DR.PNGNo platforms exist for this survey.No ferry routes are charted in the survey area, however the Alaska Marine Highway System does service King Cove and Cold Bay twice a month from May through September.Abnormal seafloor and/or environmental conditions were not observed for this survey.No 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 and Specifications 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.Benjamin K. EvansCommanding Officer, NOAA Ship RAINIER2018-03-26Scott E. BrooField Operations Officer, NOAA Ship RAINIER2018-03-26James B. JacobsonChief Survey Technician, NOAA Ship RAINIER2018-03-26Michael S. HewlettSheet Manager, NOAA Ship RAINIER2018-03-26