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 CUBE surfaces, 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 Manual, 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.VP of Survey, eTrac Inc.2019-01-24David R. Neff, C.H.All data reduction procedures conform to those detailed in the DAPR.All sounding systems were calibrated as detailed in the DAPR.SUPPORTFILES/H13165_BACKSCATTER_DN265_TA.PNGRaw backscatter from R/V Taku (DN265)Backscatter data were collected throughout the survey and are retained in the raw ALL and DB files. Every effort was made in the field to collect quality backscatter data while maintaining the primary mandate of high quality bathymetric data. While no processing or analysis of backscatter was required, eTrac Inc. verified coverage and general quality of the backscatter data collected. A beam intensity window was monitored in Qinsy during aquisiton to ensure backscatter data collection. Raw backscatter data were viewed in QPS FMGeocoder to further confirm collection criteria had been met. Shown below is an example of the unprocessed backscatter mosaic from H13165 DN265.None ExistThere were no other factors that affected corrections to soundings.eTrac Inc.2018E40000H13167Note: The junction comparison between H13165 and H13167 will be submitted with the H13167 DR.SUPPORTFILES/H13165_H12384_RESULTS_JUNCTIONTRAC.PNGH13165 - H12384 Junction ComparisonSUPPORTFILES/H13165_H12384_RESULTS_DIFFTRAC.PNGH13165 - H12384 Difference StatisticsFugro LADS2011S10000H12384The junction comparison was performed using all overlapping data between H13165 and H12384. Depth differences were evaluated using the JunctionTrac program, developed in-house by eTrac Inc. Below is a histogram of junction comparison statistics showing the difference between the junctioning surfaces and allowable TVU as well as difference statistics. 99.3096% of nodes were within allowable TVU. Depth differences between junctioning surveys were evaluated using the JunctionTrac program, developed in-house by eTrac Inc. For each junction, each CUBE weighted dynamic surface's nodes were exported to an ASCII CSV file where the fields were (Easting, Northing, Depth) for each node. A 1 meter difference surface between the junctioning datasets was also created and exported to an ASCII CSV file where the fields were (Easting, Northing, Diff) for each node. The three ASCII CSV files were then loaded into the JunctionTrac program and junction statistics were computed. A file was also created in this process to locate any nodes from the difference surface that exceed the allowable TVU, which was imported into Qimera and any identified points from JunctionTrac were analyzed. Note: the difference surfaces were created for comparison efforts only and are not submitted as surface deliverables.SVP casts were generally taken every 2 hours. Ocassionally casts would exceed a 2 hour frequency, however would never exceed a 4 hour frequency. On R/V Benthos casts were applied in both QPS QINSy and Kongsberg SIS acquisition software at the time of the cast. On R/V Taku casts were applied in QPS QINSy acquisition software at the time of the cast. Surface SVP measured at 1Hz was compared to surface speed from the current profile in realtime. If the surface velocity comparison was in excess of 2m/s at any time during survey operations, a new cast was taken. Surface sound speeds were compared in realtime and profile to profile for each cast on the vessel. Additionally, the processor reviewed profiles in Qimera to remove spurious readings within a cast, compare day-to-day casts, and to check distribution over the surveyed area, in order to better understand trends for efficient acquisition planning.SUPPORTFILES/H13165_MB_1M_MLLW_FINAL_TPU_STATISTICS_NOAA_QC_TOOLS.PNGH13165 Finalized 1m Complete Coverage MBES TPU Statistics (NOAA QC Tools)SUPPORTFILES/H13165_MB_2M_MLLW_FINAL_TPU_STATISTICS_NOAA_QC_TOOLS.PNGH13165 Finalized 2m Complete Coverage MBES TPU Statistics (NOAA QC Tools)R/V Benthos0.02500.05R/V Taku0.02500.05Standard deviation and uncertainty layers of the Dynamic Surfaces were utilized during data processing to search for features, water column noise, and systematic errors. The final 1m and 2m BAG surface's uncertainty were generated through the NOAA QC Tools and an image of the results is located below. Complete Coverage MBES (Finalized 1m CUBE weighted Dynamic Surface in NOAA QC Tools) = + 99.5% of nodes are within the allowable TPU. Complete Coverage MBES (Finalized 2m CUBE weighted Dynamic Surface in NOAA QC Tools) = + 99.5% of nodes are within the allowable TPU.Sonar system quality control checks were conducted as detailed in the quality control section of the DAPR.SUPPORTFILES/H13165_CROSSCHECK_HISTOGRAM.PNGH13165 Crossline ComparisonA comparison of crossline mileage to mainscheme mileage yields a crossline percentage of 4.35%, and is noted to be above the required 4%. A beam-by-beam statistical analysis was performed using the Cross Check tool in Qimera. A 1 meter Combined Uncertainty and Bathymetric Estimator (CUBE) weighted dynamic surface was created incorporating only the mainscheme lines and excluded crosslines. The Cross Check tool was used to perform the beam-by-beam comparison of the crossline data to the mainscheme surface. Comparisons showed excellent agreement, well above 95% of the allowable TVU. Note: This surface was created for QC only and is not submitted as a surface deliverable. The beam-to-beam crossline comparison report generated through the Qimera Cross Check tool is included in Separates II. Below is a histogram of the crossline comparison statistics showing IHO Order 1a compliance per beam.None ExistThere were no conditions or deficiencies that affected equipment operational effectiveness.All equipment and survey methods were used as detailed in the DAPR.Data Density EvaluationSUPPORTFILES/H13165_1M_DENSITYTRAC_RESULTS.PNGH13165 Finalized 1m Complete Coverage MBES Density DistributionSUPPORTFILES/H13165_2M_DENSITYTRAC_RESULTS.PNGH13165 Finalized 2m Complete Coverage MBES Density DistributionIn order to determine if the density of the data met the specified 5 soundings per node, data density was evaluated using DensityTrac in the AmiTrac program, developed in-house by eTrac Inc. Each finalized CUBE weighted dynamic surface's nodes were exported to a BBH file. The BBH file was then loaded into the DensityTrac program and density statistics were computed. For H13165 the following percentages represent the results of the density query: Complete Coverage MBES (Finalized 1m CUBE weighted Dynamic Surface ) = 99.9382% of nodes are composed from at least 5 soundings. Complete Coverage MBES (Finalized 2m CUBE weighted Dynamic Surface ) = 99.9071% of nodes are composed from at least 5 soundings.R/V Benthos100.6R/V Taku100.6The R/V Benthos is a 10 meter aluminum catamaran equipped with a custom over-the-side (port) multibeam hydraulic pole mount. The R/V Taku is a 10 meter aluminum catamaran equipped with a custom stern multibeam pole mount.Refer 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 are discussed in the following sections.Kongsberg MBES2040CR2SonicMBES2024ApplanixPositioning and Attitude SystemPOSMV 320 V5AMLSound Speed SystemBase.XAMLSound Speed SystemSmart.XNote: R/V Benthos utilized a dualhead Kongsberg 2040C multibeam echosounder system, an AML Base.X for the sound speed system and a POSMV 320 V5 for the positioning system. R/V Taku utilized a dualhead R2Sonic 2024 multibeam echosounder system, an AML Smart.X for the sound speed system and a POSMV 320 V5 for the positioning system.No Feature Object Catalog was used. Qimera was used as the primary processing software, which included feature management.Complete MBESH13165_MB_1m_MLLW_FinalBAGNOAA_1m2.2201Complete MBESH13165_MB_2m_MLLW_FinalBAGNOAA_2m1823.72SUPPORTFILES/H13165_1M_SURFACE_COVERAGE.PNGH13165 Delivered 1m CUBE Surface Coverage GraphicSUPPORTFILES/H13165_2M_SURFACE_COVERAGE.PNGH13165 Delivered 2m CUBE Surface Coverage GraphicA 1m surface and 2m surface are provided meeting complete coverage MBES with backscatter specifications for H13165. These surfaces have been thresholded based on the specifications set forth in the HSSD. SUPPORTFILES/H13165_CONTOUR_COMPARISON_US4FL92M.PNGH13165 12ft, 18ft, 30ft, and 60ft Contour Comparison (US5FL92M)SUPPORTFILES/H13165_CONTOUR_COMPARISON_US4FL92M_NEWGROUND_DETAIL.PNGDetailed View of H13165 12ft and 18ft Contour Comparison on on New Ground (US5FL92M)SUPPORTFILES/H13165_SOUNDING_COMPARISON_US4FL92M.PNGH13165 Sounding Comparison (ENC US5FL92M)US5FL92M10false800002016-12-052016-12-05Contour Comparison Results: New Ground Shoal has predominantly receded inward. The 6 foot and 12 foot contours charted on and around New Ground no longer exist. 18 foot contour has receded inward approximately 250 feet from the charted contour. The 30 foot contour has receded approximately 350 feet from the charted contour. The 30 foot contour at the southern end of H13165 has receded shoreward on average 550 feet from the charted contour. The 60 foot contour has receded shoreward on average 760 feet from the charted contour. Sounding Comparison Results: In areas where the contour has changed, as noted above, and where a feature was detected, soundings differ from the charted depths. In general for H13165, the soundings are in excellent agreement with the chart with no major discrepancies. Soundings are generally within 1 to 2 feet of each other. Occasionally soundings differ by 3 to 4 feet, however depth differences generally appear to be minimal. Depth differences are not biased in any particular direction to support a systematic error. There were 40 new features found in H13165 and added to the Final Feature File (FFF). Each feature was given a unique identifier in the "userid" field of the .000 S-57 file (format 5XXX). Refer to the FFF for determinations and recommendations of each feature. No channels exist for this survey.No shoals or hazardous features exist for this survey.No AWOIS Items were assigned for this survey.There were 6 charted features assigned to H13165. The assigned features are retained in the Final Feature File (FFF). Each feature in the FFF has been given a unique identifier in the "userid" field of the .000 S-57 file (format 5XXX). Refer to the FFF for determinations and recommendations of each feature.No Maritime Boundary Points were assigned for this survey.6H13165_DtoN_012018-09-25H13165_DtoN_02_032018-12-04H13165_DtoN_042018-12-04H13165_DtoN_052018-12-04H13169_DtoN_062018-12-04There were 6 DtoNs which included 40 features in total, found in H13165, and added to the Final Feature File (FFF). Each feature in the FFF has been given a unique identifier in the "userid" field of the .000 S-57 file (format H13165_DtoN_XX). Refer to the FFF for determinations and recomendations of each feature. Note: All DtoNs were included in the number of new, uncharted features within section D.1.5.A chart comparison was conducted for H13165 using Qimera and Caris HIPS and SIPS. Contours and soundings were compared against the largest scale ENC US4FL92M to accomplish the chart comparison. The methods and results of the comparison are detailed below. Contour Comparison Method: Using the 1 meter CUBE weighted Dynamic Surface, the 6 foot, 12 foot, 18 foot, 30 foot and 60 foot contours were generated in Qimera and displayed against the charted contour. Additionally, the 1 meter CUBE weighted Dynamic Surface was viewed by a custom color band range based on the contour intervals (6ft, 12ft, 18ft, 30ft, 60ft). The results of the comparison are described below, followed by 1-2 images of example areas. Sounding Comparison Method: Using the same 1 meter CUBE weighted Dynamic surface, soundings were generated in Caris HIPS and SIPS. Soundings were displayed against the charted soundings and a visual comparison was made. The results of the comparison are described below, followed by 1-2 images of example areas.5 locations of drop camera imagery were obtained in accordance with Appendix I of the Project Instructions in areas designated by the feature object class springs (SPRING) in the Project Reference File (PRF). Drop camera imagery was obtained instead of physical bottom samples due to the vincity of the National Marine Sanctuary. Drop camera imagery was used to define the NATSUR but was insuffient for defining the NATQUA and COLOUR. A brief description of the results is listed below. F1: coral, sand F2: coral F3: coral, sand F4: sand, shells F5: coral, sand Detailed information and images of the bottom samples listed above are located in the Final Feature File (FFF). Each bottom sample has been given a unique identifier in the "userid" field of the .000 S-57 file (format FX).No overhead features exist for with survey.No new surveys or further investigations are recommended for this area.No shoreline exists for this survey.No platforms exist for this survey.No significant features exist for this survey.No construction or dredging exist for this survey.No submarine features exist for this survey.SUPPORTFILES/H13165_FERRYROUTE.PNGFerry Route (blue line)SUPPORTFILES/H13165_FERRYTERMINAL_KEYWEST.PNGFerry Terminal - Key West Ferry BuildingSUPPORTFILES/H13165_FERRYTERMINAL_FORTJEFFERSON.PNGFerry Terminal - Fort Jefferson Boat Dock1 uncharted ferry route is located within the survey limits of H13165. The ferry route is called Key West-Fort Jefferson or Dry Tortugas Ferry. The ferry terminals for this route are located at the Key West Ferry Building in Key West, Florida and the Fort Jefferson Boat Dock in Dry Tortugas, Florida.SUPPORTFILES/H13165_ATON_OBSERVATION.PNGH13165 Visual Observation of Damaged AtoNThere were 3 charted AtoNs assigned in H13165. The 3 AtoNs were found to serve their intened pupose and are retained in the Final Feature File (FFF). 1 AtoN although serving its intended purpose apears to be damaged. This was noted in the FFF and an image of the damaged AtoN is displayed below. Each feature was given a unique identifier in the "userid" field of the .000 S-57 file (format 5XXX). Refer to the FFF for determinations and recommendations of each feature. Note: All AtoNs were included in the number of charted features within section D.1.4. No new insets are recommended for this area.No prior surveys exist for with survey.UTM Zone 17NNorth American Datum of 1983 (NAD83)VDatumITRF_to_MLLW_FL_KEYS.binIn order to reference soundings to MLLW, a VDatum separation method was applied to the Qinsy DB files via a separation file in the aquisition softwares. Note: The vertical control methods are further addressed in the HVCR and DAPR.Mean Lower Low WaterReference OPR-H355-KR-18 Horizontal and Vertical Control Report.4 Nautical Miles North of the QuicksandsH131656Florida40000United StatesComplete Coverage MBES with BackscattereTrac Inc.Florida Keys National Marine Sanctuary and VicinityFlorida KeysOPR-H355-KR-182018-07-20David Neff, ACSM C.H. Universal Transverse Mercator (UTM)Multibeam Echo SounderMultibeam Echo Sounder BackscatterAll times are UTC. The purpose of this survey is to update existing NOS nautical charts. H13165 will cover approximately 31 square nautical miles of survey area 4 nautical miles north of the Quicksands. SUBCONSULTANT: Geodynamics LLC, 310A Greenfield Dr., Newport, NC 98570 Any 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 17N, MLLW. All references to other horizontal or vertical datums in this report are applicable to the processed hydrographic data provided by the field unit.metersNavigable Area2018-11-192018-09-07UTCAtlantic Hydrographic Branch2018Contractor24.68646482.4863124.62099782.339691SUPPORTFILES/H13165_SURVEY_LIMITS_OVERVIEW.PNGSurvey Limits (blue area)SUPPORTFILES/H13165_SURVEY_LIMITS.PNGSurvey Limits (black line)eTrac Inc. conducted hydrographic survey operations in the Florida Keys National Marine Sanctuary and surrounding vicinity. H13165 covers approximately 31 square nautical miles of survey area. 1413 linear nautical miles were acquired during the survey. H13165 is located approximately 4 nautical miles north of The Quicksands off the coast of Key West, Florida. Survey was conducted within these limits between September 7, 2018 (DN250) and November 19, 2018 (DN323).All data were acquired in accordance with the requirements in the Project Instructions and specifications set forth in the Hydrographic Survey Specifications and Deliverables 2018 Edition (HSSD 2018).file:///H:/Survey/H13165_H355_KR_18/AHB_H13165/01_SAR/Reports/Survey/Descriptive_Report/Report/SupportFiles/H13165_Survey_Limits_Overview.PNGSurvey Coveragefile:///H:/Survey/H13165_H355_KR_18/AHB_H13165/01_SAR/Reports/Survey/Descriptive_Report/Report/SupportFiles/H13165_Coverage_Gap_1_2.pngH13165 Survey Coverage Gaps outside survey boundary (area 1)file:///H:/Survey/H13165_H355_KR_18/AHB_H13165/01_SAR/Reports/Survey/Descriptive_Report/Report/SupportFiles/H13165_Coverage_Gap_3.pngH13165 Survey Coverage Gap outside survey boundary (area 2)Survey Coverage was in accordance with the requirements in the Project Instructions and HSSD 2018. H13165 was surveyed to Complete Coverage with backscatter standards set forth in the HSSD 2018. Note: There are 3 coverage gaps in the MBES coverage within areas of H13165. All 3 coverage gaps are outside the survey boundary and therefore are not classified as holidays. The purpose of this survey is to update existing National Ocean Service (NOS) nautical charts.The entire survey is adequate to supersede previous data.Survey H13165 is accurate to International Hydrographic Organization (IHO) Order 1a as required per the HSSD 2018.Benthos0001025390000Taku00032920000000013544.3559000000535002018-09-072018-09-082018-09-092018-09-102018-09-112018-09-122018-09-132018-09-142018-09-152018-09-162018-09-172018-09-192018-09-202018-09-222018-09-232018-09-242018-09-252018-09-262018-10-122018-10-132018-10-142018-10-202018-10-212018-11-132018-11-19file:///H:/Survey/H13165_H355_KR_18/AHB_H13165/01_SAR/Reports/Survey/Descriptive_Report/Report/SupportFiles/H13165_Survey_Limits.PNGFigure 2: