OPR-N305-FA-18Puget Sound, WANorthwest WashingtonNOAA Ship FAIRWEATHERH129933Holmes Harbor to Elger BayWashingtonUnited States400002018CDR Marc Moser, NOAANavigable Area2018-09-062018-09-272018-10-05Multibeam Echo SounderMultibeam Echo Sounder BackscattermetersUniversal Transverse Mercator (UTM)UTCPacific Hydrographic BranchNOAAThe survey area is located in Northwest Washington within the sub locality of Holmes Harbor to Elger Bay.48.1311820278122.57110505648.0167104722122.450789028H12993 sheet limits (in blue) overlaid onto Chart 18441file:///H:/2018_Data/OPR-N305-FA-18_Puget%20Sound/H12993/Survey_Files/DR_Images/H12993_Sheet_Limits.pngData were acquired to the survey limits in accordance with the requirements in the Project Instructions and the April 2018 NOS Hydrographic Surveys Specifications and Deliverables (HSSD) as shown in Figure 2. 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 maneuvering the survey vessel in close proximity to kelp, the shoreline, or due to time constraints in the project area. An example of such an area is shown in Figure 2.H12993 Example of where the NALL was not reached due to time constraintsfile:///H:/2018_Data/OPR-N305-FA-18_Puget%20Sound/H12993/Survey_Files/DR_Images/H12993_NALL_Inside_Sheet_Limits.pngThe primary purpose of this project is to provide contemporary surveys for updating National Ocean Service nautical charts and products in an area which is critical to the nation's economy. The new bathymetric data will enhance the safety of cargo and tanker traffic transiting to and from the ports of Seattle and Tacoma; it will also support military traffic transiting to and from Bangor Naval Submarine Base, commercial/tribal fishing and recreational boating. 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 H12993 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 Coverage with complete MBES backscatterThe entirety of H12993 was acquired with complete coverage MBES, meeting the requirements listed above and in the HSSD. See Figure 3 for an overview of coverage. H12993 survey coverage overlaid onto Chart 18441file:///H:/2018_Data/OPR-N305-FA-18_Puget%20Sound/H12993/Survey_Files/DR_Images/H12993_Coverage_Overview.pngFA 2805020.700000000FA 2806060.14000009.230FA 2807071.430000000FA 2808073.9100000000226.18000009.2304.08600012.892018-09-272018-10-042018-10-05Refer to the OPR-N305-FA-18 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 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. 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 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 -0.01 meters (with mainscheme being shoaler) and 95% of nodes falling within +/- 0.27 meters (Figure 5). For the respective depths, the difference surface was compared to the allowable NOAA uncertainty standards. In total, 99.98% of the depth differences between H12993 mainscheme and crossline data were within allowable NOAA uncertainties.Overview of H12993 Crosslinesfile:///H:/2018_Data/OPR-N305-FA-18_Puget%20Sound/H12993/Survey_Files/DR_Images/H12993_Crossline_Overview.pngH12993 Crossline and Mainscheme Difference Statisticsfile:///H:/2018_Data/OPR-N305-FA-18_Puget%20Sound/H12993/Survey_Files/DR_Images/H12993_Crossline_Difference_Statistics.png013.6ERS via VDATUM280x (All Launches)2N/A0.5In addition to the usual a priori estimates of uncertainty provided via device models for vessel motion and VDatum, real-time and post-processed uncertainty sources were also incorporated into the depth estimates of survey H12993. 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.No junctions exist for this survey.Sonar 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 Grass and KelpSea grass and kelp were present throughout the nearshore survey area and at times, indistinguishable from the seafloor (Figure 6). In areas where they were distinguishable, the soundings on the vegetation were rejected to enable more accurate representation of the true seafloor. Where vegetation was indistinguishable, all soundings were retained. Furthermore, in some areas, patches of dense kelp prohibited safe navigation of the survey vessels. The limits of these areas were then used to define the NALL (Figure 7). Documentation can be found in the vessel boat sheets, which are located in the Detached Positions folder.Example of sea grass presencefile:///H:/2018_Data/OPR-N305-FA-18_Puget%20Sound/H12993/Survey_Files/DR_Images/H12993_Sea_Grass_Overview.pngAreas where NALL is defined by kelp limitsfile:///H:/2018_Data/OPR-N305-FA-18_Puget%20Sound/H12993/Survey_Files/DR_Images/H12993_Kelp_Overview.pngSound Speed IssuesIn certain areas, particularly around and throughout the approach to Holmes Harbor, small sound speed issues were apparent, visible primarily as "smiles" (see Figure 8). Surfaces were not significantly impacted, and the data meet NOAA allowable uncertainty parameters. As such, the data remain sufficient to supersede previous data.Example of area with sound speed artifactsfile:///H:/2018_Data/OPR-N305-FA-18_Puget%20Sound/H12993/Survey_Files/DR_Images/H12993_Sound_Speed_Issues.pngCasts were conducted at a minimum of one 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. All sound speed methods were used as detailed in the DAPR.All equipment and survey methods were used as detailed in the DAPR.HolidaysH12993 data were reviewed in CARIS HIPS and SIPS for holidays in accordance with Section 5.2.2.3 of the HSSD. One holiday which meets the definition described in the HSSD for complete coverage was 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. The holiday is a result of acoustic shadowing due to lack of coverage on the inshore side of the object, arising from a rapid change in seafloor height (Figure 9). The hydrographer is confident that the least depth of the object was captured. Holiday due to acoustic shadowingfile:///H:/2018_Data/OPR-N305-FA-18_Puget%20Sound/H12993/Survey_Files/DR_Images/H12993_Holiday_Overview.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 H12993. For a graphical representation of compliance with uncertainty standards, see Figure 10 below.H12993 Allowable Uncertainty statisticsfile:///H:/2018_Data/OPR-N305-FA-18_Puget%20Sound/H12993/Survey_Files/DR_Images/H12993_Allowable_Uncertainty.pngDensityThe surface was analyzed using the HydrOffice QC Tools Grid QA feature and the results are shown in Figure 11 below. Density requirements for H12993 were achieved with at least 99.5+% of the surface nodes containing five or more soundings as required by HSSD Section 5.2.2.3. H12993 Data Density statisticsfile:///H:/2018_Data/OPR-N305-FA-18_Puget%20Sound/H12993/Survey_Files/DR_Images/H12993_Data_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 Kongsberg systems. All backscatter were processed to GSF files, and a floating point mosaic per sonar frequency was created by the field unit via Fledermaus FMGT 7.8.5. 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. This allowed data of the same frequency to be mosaicked together across the different platforms. See Figure 12 for a table of the calibration values entered into the Processing Settings within FMGT. Approximate inter-calibration corrections for offsets between sonar systems were applied to the mosaic. See Figure 13 for a greyscale representation of the complete mosaic. Backscatter Calibration Valuesfile:///H:/2018_Data/OPR-N305-FA-18_Puget%20Sound/H12993/Survey_Files/DR_Images/H12993_Backscatter_Table.pngBackscatter Mosaicfile:///H:/2018_Data/OPR-N305-FA-18_Puget%20Sound/H12993/Survey_Files/DR_Images/H12993_Backscatter_Mosaic.pngCarisHIPS/SIPS10.4.5QPSFledermaus FMGT7.8.5NOAA Extended Attribute Files Version 5.7H12993_MB_VR_MLLW_Final.csarCARIS VR Surface (CUBE)1-80.24147.77NOAA_VRComplete MBESH12993_MB_VR_MLLW.csarCARIS VR Surface (CUBE)1-80.24147.77NOAA_VRComplete MBESThe NOAA CUBE parameters defined in the HSSD were used for the creation of all CUBE surfaces for H12993. 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 steep slopes and dynamic nature of the seafloor.Data LogsData acquisition and processing notes are included in the acquisition and processing logs, and additional processing such as final tide and sound speed application are noted in the H12993 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 H12993.Mean Lower Low WaterTCARI9444900.tidFinal Approved9447130.tidFinal ApprovedH12993_H12994.tcFinal2018-10-122018-11-01ERS via VDATUMVDatumShape_xyNAD83-MLLW_geoid12bERS methods were used as the final means of reducing H12993 to MLLW for submission following the successful application of SBETs. The final TCARI grid was used to reduce all features to MLLW.North American Datum 1983Projected UTM 10Vessel kinematic data were post-processed using Applanix POSPac processing software and RTX 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. Differential correctors from the US Coast Guard beacon at Whidbey Island (302kHz) were used in real-time for acquisition when not otherwise noted in the acquisition logs, and were the sole method of positioning of detached positions (DP) and bottom samples.A comparison was performed between survey H12993 and ENC US4WA11M 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 to a VR grid by extracting all soundings from the chart and creating an interpolated TIN surface which could be differenced with the surface from H12993. All data from H12993 should supersede charted data. In general, surveyed soundings agree with the majority of charted depths. A full discussion of the comparison follows below.US4WA11M80000372018-04-272018-11-28falseSoundings from H12993 are in general agreement with charted depths on ENC US4WA11M, with most depths agreeing to 2 fathoms as shown in Figure 14. The largest differences are seen in steeper areas where differences range to 10 fathoms as seen in Figure 16. To more accurately visualize trends within these differences, an 8 meter TIN surface was interpolated from the ENC sounding layer. This surface was then differenced with a corresponding 8 meter surface from H12993 and visualized in Figure 14. In this difference surface red colors indicate H12993 was shoaler than the ENC US4WA11M, green colors indicate agreement, and blue colors indicate H12993 was deeper than ENC US4WA11M. As expected, the flat plain of Holmes Harbor is in close agreement with ENC US4WA11M while the more dynamic Saratoga Passage and the entrance to Holmes Harbor exhibit areas both shoaler and deeper than those expressed in ENC US4WA11M. As mentioned previously, the areas of most rapid depth change experience the greatest inaccuracies. There does not appear to be a pattern determining why these areas of rapid change are either shoaler or deeper than charted. Contours from H12993 are in general agreement with charted contours on ENC US4WA11M as shown in Figure 17. The largest differences are seen in Elger Bay, from East Point to Rocky Point, in Honeymoon Bay and in the southeastern area of Holmes Harbor where surveyed contours differ by up to 100 meters. In most cases, the surveyed contours are inshore of the charted contours.Difference surface between H12993 and interpolated TIN surface from US4WA11Mfile:///H:/2018_Data/OPR-N305-FA-18_Puget%20Sound/H12993/Survey_Files/DR_Images/H12993_ENC_Difference_Surface.pngDifference surface statistics between H12993 and interpolated TIN surface from US4WA11Mfile:///H:/2018_Data/OPR-N305-FA-18_Puget%20Sound/H12993/Survey_Files/DR_Images/H12993_8m_US4WA11M_Diff.pngClose up of area where significant differences between H12993 soundings (in white) and ENC US4WA11M depths (in black)file:///H:/2018_Data/OPR-N305-FA-18_Puget%20Sound/H12993/Survey_Files/DR_Images/H12993_Sounding_Diff.pngOverview of H12993 contours overlaid onto ENC US4WA11Mfile:///H:/2018_Data/OPR-N305-FA-18_Puget%20Sound/H12993/Survey_Files/DR_Images/H12993_Contour_Diff.pngNo Maritime Boundary Points were assigned for this survey. One feature containing the label PA was assigned for this survey. The feature in question is a pile and is located on the eastern shoreline of Holmes Harbor roughly 1600m south of Baby Island. The feature was charted incorrectly and repositioned roughly 145m to the southeast. There are two piles in the new position, although only one is attributed due to their proximity to each other. The piles are made out of wood and are always visible. Survey H12993 has 15 new features that are addressed in the H12993 Final Feature File. Of these features, there are 2 new Underwater Rocks of which 0 are submitted as DTONs, 3 new kelp features, 1 new pile, 1 new shoreline construction, 6 new seabed areas, and 1 new land area in conjunction with 1 new land elevation feature.No shoals or potentially hazardous features exist for this survey. The entirety of Holmes Harbor is an unrestricted general anchorage area. Depths range from 42 fathoms at the head of the harbor all the way to the shoreline. No channels exist for this survey. There are no precautionary areas, safety fairways, traffic separation schemes, pilot boarding areas, or channel and range lines within the survey limits.Six bottom samples were acquired in accordance with the Project Instructions for survey H12993. All bottom samples were entered in the H12993 Final Feature File. See Figure 18 for a graphical overview of sample locations. H12993 Bottom Sample Locationsfile:///H:/2018_Data/OPR-N305-FA-18_Puget%20Sound/H12993/Survey_Files/DR_Images/H12993_Bottom_Sample_Locations.pngFairweather personnel conducted limited shoreline verification and reconnaissance, utilizing traditional shoreline methods, at times near predicted negative or low tides within the survey limits. Inaccessible features inshore of the 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 NALL" as per HSSD Section 7.3.1. Annotations, information, and diagrams collected in DP forms and boat sheets during field operations were scanned and included in the Separates I Detached Positions folder. Shoreline verification procedures for H12993 conform to those detailed in the DAPR.No prior survey comparisons exist for this survey.One ATON was assigned for this survey. The ATON was on-station and serving its intended purpose. The ATON was attributed in the Final Feature Final with the description of "Retain" as per HSSD Section 7.3.5.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.No abnormal seafloor and/or environmental conditions exist 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 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.CDR Marc MoserChief of Party2019-02-14CHST Samuel CandioChief Survey Technician2019-02-14HST Simon SwartSheet Manager2019-02-14