Due to familiarity with the software, chart comparisons were conducted in CARIS using an exported BAG file of the H13172_MB_1m_MLLW_Final surface. A combination of sounding selection layers and user-defined depth ranges were used to compare surveyed soundings to charted depths using tools within the CARIS software. The sounding selection layer was generated from the H13172_MB_1m_MLLW_Final surface using a shoal biased, single-defined radius of 150 and 300 meters, which provided sufficient soundings across the survey area with which to compare charted depths and contours, depending on the scale of the chart. User-defined color maps were generated to match the contour intervals present on US5FL11M, US4FL10M, US4FL18M and USCG07M (Figures 21 - 24).Color range used to compare H13172 surveyed depths to charted depths (US5FL11M).SupportFiles\Fig21-H13172-Chart_Comparison_US5FL11M-ColorMap.pngColor range used to compare H13172 surveyed depths to charted depths (US4FL10M).SupportFiles\Fig22-H13172-Chart_Comparison_US4FL10M-ColorMap.pngColor range used to compare H13172 surveyed depths to charted depths (US4FL18M).SupportFiles\Fig23-H13172-Chart_Comparison_US4FL18M-ColorMap.pngColor range used to compare H13172 surveyed depths to charted depths (USGC07M).SupportFiles\Fig24-H13172-Chart_Comparison_USGC07M-ColorMap.pngA total of seven bottom samples were acquired within the H13172 survey area. Another two were attempted, but no sample obtained. Refer to the Final Feature File for additional information.NOAA Local Notice to Mariners (LNM) were reviewed subsequent to the date of the Project Instructions and before the end of the survey for RNC 11415. The last LNM reviewed for Chart: 11415, Current Edition: 13, Print Date: Nov. /2018, Tampa Bay Entrance; Manatee River Extension was LNM 14/19, 7th Dist posted on 3/28/2019 to add a Sounding in Feet. No LNM were issued within the survey bounds subsequent to the date of the Project Instructions and the before the end of the survey. The 0.9, 1.8, 3.6, 5.4 and 9.1-meter contours are present on chart US5FL11M within the survey area. In general survey data indicate that the contours have shifted east and landward, particularly within the northeast portion of the survey area. For example, there is only one area where survey data indicate soundings between 0 and 0.9 meters while survey data do not indicate depths of this range within the isolated contours to the south (Figure 25). In addition, survey data indicate the 0.9-1.8 meter depth range covers less area than currently charted. Data indicate several currently charted isolated contours no longer exist while at least two new areas outside the currently charted contour are present to the south (Figure 26). Survey data also indicate the 1.8 to 3.6-meter depth range covers less area than currently charted. Data indicate many of the isolated contours west, southwest and south of the main contour no longer exist while in some areas surveyed soundings less than or equal to 3.6 meters extend seaward of the currently charted contour (Figure 27). Survey data indicate surveyed soundings between 3.6 and 5.4 meters are generally located within the currently charted depth area. However, it is evident in the north-central portion of the survey area surveyed soundings equal to or less than 5.4 meters extend seaward of the currently charted contour. In addition, survey data indicate some isolated charted contours are no longer present while new isolated contours exist (Figure 28). Survey data indicate surveyed soundings between 5.4 and 9.1 meters are generally within or near the charted contour, though data indicate several contours have shifted, mainly to the southeast and three isolated charted contours in the southwest portion of the survey area no longer exist. (Figure 29). It was difficult to make generalizations about the degree of agreement between charted depths and the selected sounding layer generated from survey data. While review indicates the majority of surveyed soundings are deeper than charted depths by 30 cm - 2.5 meters, a substantial number of surveyed soundings were found to be shallower than charted depths by up to 2 meters, mainly in the northeastern portion of the survey area. These correlate with the above discussion noting the differences between a surface generated from surveyed soundings and charted depths. The shallow soundings were submitted for review and have been added to the FFF.472019-05-13false2019-03-1140000US5FL11MComparison of charted 0.9-meter contour to surveyed depths in northeastern portion of H13172. H13172_MB_1m_MLLW_Final surface colored using colormap shown in Figure 21. Charted 0.9-meter contour in red. Red box shows area where survey data indicate surveyed soundings are equal to or less than 0.9 meters.SupportFiles\Fig25-H13172-Chart_Comparison_US5FL11M-1.pngComparison of charted 1.8-meter contour to surveyed depths in northeastern portion of H13172. H13172_MB_1m_MLLW_Final surface colored using colormap shown in Figure 21. Charted 1.8-meter contour in orange. Orange boxes show areas where survey data indicate surveyed soundings are between 0.9 and 1.8 meters.SupportFiles\Fig26-H13172-Chart_Comparison_US5FL11M-2.pngComparison of charted 3.6-meter contour to surveyed depths in northeastern portion of H13172. H13172_MB_1m_MLLW_Final surface colored using colormap shown in Figure 21. Charted 3.6-meter contour in yellow. Yellow boxes show areas where survey data indicate surveyed soundings between 1.8 and 3.6 meters extend seaward of the currently charted contour.SupportFiles\Fig27-H13172-Chart_Comparison_US5FL11M-3.pngComparison of charted 5.4-meter contour to surveyed depths in northeastern portion of H13172. H13172_MB_1m_MLLW_Final surface colored using colormap shown in Figure 21. Charted 5.4-meter contour in green. Green boxes show areas where survey data indicate surveyed soundings between 3.6 and 5.4 meters extend seaward of the currently charted contour. Black circles indicate areas where survey data indicate depths greater than 5.4 meters within 5.4-meter charted contours.SupportFiles\Fig28-H13172-Chart_Comparison_US5FL11M-4.pngComparison of charted 9.1-meter contour to surveyed depths in northeastern portion of H13172. H13172_MB_1m_MLLW_Final surface colored using colormap shown in Figure 21. Charted 9.1-meter contour in blue. Blue boxes show areas where survey data indicate surveyed soundings between 5.4 and 9.1 meters extend southeast of the currently charted contour.SupportFiles\Fig29-H13172-Chart_Comparison_US5FL11M-5.pngNOAA Local Notice to Mariners (LNM) were reviewed subsequent to the date of the Project Instructions and before the end of the survey for RNC 11412. The last LNM reviewed for Chart: 11412, Current Edition: 49, Print Date: Feb. /2019, Tampa Bay and St. Joseph Sound was LNM 14/19, 7th Dist posted on 3/28/2019 to add a Sounding in Feet. No LNM were issued within the survey bounds subsequent to the date of the Project Instructions and the before the end of the survey. Charted contours on US4FL10M are more generalized than those on US5FL11M, but follow the same trend; no large discrepancies between charted depths were observed between the two charts. Observations made for US5FL11M are valid for US4FL10M with one exception. The 10.9-meter contour is present on US4FL10M that was not present on US5FL11M. Survey data indicate surveyed soundings 9.1-10.9 meters are generally located within the charted contour but that surveyed soundings greater than 10.9 meters extend inside the currently charted contour area (Figure 30).342019-05-13false2019-03-1880000US4FL10MComparison of charted 10.9-meter contour to surveyed depths in western portion of H13172. H13172_MB_1m_MLLW_Final surface colored using colormap shown in Figure 22. Charted 10.9-meter contour in blue.SupportFiles\Fig30-H13172-Chart_Comparison_US4FL10M-1.pngNOAA Local Notice to Mariners (LNM) were reviewed subsequent to the date of the Project Instructions and before the end of the survey for RNC 11424. The last LNM reviewed for Chart: 11424, Current Edition: 21, Print Date: Apr. /2019, Lemon Bay to Passage Key Inlet was LNM 14/19, 7th Dist posted on 3/28/2019 to add a Sounding in Feet. No LNM were issued within the survey bounds subsequent to the date of the Project Instructions and the before the end of the survey. The very southern portion of the survey area overlaps a small area of chart US4FL18M mainly between the charted 9.1 and 10.9-meter contours. Survey data indicate surveyed soundings greater than 10.9 meters extend eastward of the currently charted contour and while there are some isolated areas less than 9.1 meters at the very edge of the chart overlap, there is a charted contour indicating charted depths less than 9.1 meters; surveyed soundings indicate that depths in this area are 9.1 meters or deeper (Figure 31). 202018-11-19false2018-03-0580000US4FL18MComparison of charted 9.1-meter contour to surveyed depths in southern portion of H13172. H13172_MB_1m_MLLW_Final surface colored using colormap shown in Figure 23. Charted 9.1-meter contour in red and yellow. Yellow contour indicates area where surveyed soundings are greater than 9.1 meters and deeper than the currently charted contour.SupportFiles\Fig31-H13172-Chart_Comparison_US4FL18M-1.pngNOAA Local Notice to Mariners (LNM) were reviewed subsequent to the date of the Project Instructions and before the end of the survey for RNC 11420. The last LNM reviewed for Chart: 11420, Current Edition: 32, Print Date: Oct. /2018, Havana to Tampa Bay was LNM 12/19, 7th Dist posted on 3/28/2019 to delete Fort Jefferson Lighted Buoy L. No LNM were issued within the survey bounds subsequent to the date of the Project Instructions and the before the end of the survey. Due to the scale of the chart, the contours are broad and the soundings sparse as compared to the previous charts. The 5.4 and 9.1-meter contours are present within the survey area. In general, it is evident that surveyed soundings of a particular depth range fall within the charted contours, though there are some differences. Survey data indicate surveyed soundings less than 5.4 meters extend north of the currently charted contour in the north, northeastern and central-eastern portions of the survey area while survey data indicate surveyed soundings greater than 9.1 meters are present within the isolated charted 9.1-meter contour in the southwest portion of the survey area. Survey data also indicate several isolated contours are present that are not currently charted (Figure 32). Surveyed soundings are generally deeper than charted depths by 30 cm - 3 meters, though there is one charted 10-meter depth in the south central portion of the survey area that matches with surveyed soundings well (Figure 33). 342019-05-08false2019-03-11350000US3GC07MComparison of charted contours to surveyed depths for H13172. H13172_MB_1m_MLLW_Final surface colored using colormap shown in Figure 24. Charted 5.4-meter contour in red and charted 9.1-meter contour in green. Red and green boxes indicate areas where surveyed soundings shallower than the respective contour extend past the respective contour.SupportFiles\Fig32-H13172-Chart_Comparison_USGC07M-1.pngComparison of charted depths to surveyed soundings for H13172. H13172_MB_1m_MLLW_Final surface colored using colormap shown in Figure 24.SupportFiles\Fig33-H13172-Chart_Comparison_USGC07M-2.pngPrior to starting survey operations, the Composite Source File (CSF) indicated 14 charted features within the survey limits that were assigned for investigation: one Aid to Navigation (with fog signal and light not counted as separate features), one Fish Haven Area, one pipeline, two wrecks, two discrete obstructions, one area obstruction, two land areas and four shoreline features. Unassigned features include five spoil areas partially within the survey area and the navigation fairway south of Egmont Channel.Two discrete obstructions were submitted as Dangers to Navigation for this survey. In addition, a substantial number of sounding features where survey data indicate shallower depths than currently charted were submitted for review. Four were accepted as DtoNs. Refer to the Final Feature File and Supplemental Survey Records and Correspondence for additional information. H13172 is south of Egmont Channel and the survey area covers a portion of the safety fairway around Egmont Channel. In general, surveyed soundings are deeper than charted depths in this area but there are two areas in particular where surveyed soundings are shallower than charted depths (Figure 34).Comparison of charted depths to surveyed soundings within the safety fairway south of Egmont Channel.SupportFiles\Fig34-H13172-Fairway.pngNo Maritime Boundary Points were assigned for this survey. An additional nine discrete features and one area feature were added to the Final Feature File that were not addressed as Dangers to Navigation due to factors such as charted depths, proximity to charted features, or proximity to other DtoNs. Refer to the Final Feature File for additional information.One ATON was assigned for investigation during this survey and was determined to be on station. Please refer the the Final Feature File and ATON_Data in the deliverables folders for additional information. In addition, the field took fixes on three small buoys near the Egmont Key Ruins, which were called 'swim buoys' in the logs; one of the fixes fell within the bounds of the survey area. Please refer to Detached_Positions in the deliverables folders for additional information.No new insets are recommended for this area.The inshore limit of hydrography and feature verification for Navigable Area Surveys is the Navigable Area Limit Line (NALL), as stated in section 1.3.2 of the HSSD (2018). For this survey the NALL consisted of the 3.5-meter depth contour, which was defined along the northeastern corner of the survey area, seaward of Egmont Key. Two shoreline features and two shoreline/landarea features were assigned for investigation. Refer to the FFF for additional information.No new surveys or further investigations are recommended for this area.No overhead features exist for this survey.One pipeline, labeled as the 'Gulfstream Natural Gas System' in the CSF file, extends generally northwest/southeast through the survey area. Four potential exposures were identified along the pipeline and submitted to BSEE as per the HSSD (2018). Refer to the Supplemental Survey Records and Correspondence and the Final Feature File for additional information.An area of abnormal seafloor was identified where the MBES appears to have had difficulty detecting the bottom. Review of the SSS data indicates bottom change in this area. Where the seafloor could not be accurately determined from the bathymetry data, the MBES data was rejected completely; nadir coverage still exists (Figure 35).Abnormal seafloor area where the MBES had difficulty detecting bottom.SupportFiles\Fig35-H13172_Abnormal_Seafloor_Conditions.pngNo present or planned construction or dredging exist within the survey limits.No platforms exist for this survey.No ferry routes or terminals exist for this survey.No prior survey comparisons exist for this survey.H13172 Survey CoverageSupportFiles\Fig2-H13172_Survey_Coverage.png4507026.792018-10-172018-10-182018-11-132018-11-142018-11-172018-11-182018-11-192018-11-202018-11-212018-11-222018-11-232018-11-242018-11-292019-11-302019-02-052019-02-062019-02-072019-02-082019-02-102019-02-112019-02-122019-02-212019-02-222019-02-232019-02-242019-03-092019-03-252019-03-262019-03-290.000.000.00871.900.005.370.000.0046.790.00JQN00027J7080.000.000.00871.900.000.000.0046.790.00Detached Positions include CTD fixes (including two re-casts), one ATON fix and one fix of a small uncharted buoy near Egmont Ruins (called a 'swim buoy' in the field logs). Bottom sample fixes are not included in Detached Positions because there is a separate entry for those. Bottom sample total includes only those for which a sample was obtained; please refer to section D.1.7 for additional information. The total SNM includes the main H13172 survey area, a detached assigned investigation and a small MB coverage only area in the northeast portion of the survey area connected to the main survey area by a NALL investigation line.The entire survey is adequate to supersede previous data.All waters in the survey area (except Sheet 4)Complete coverageAll waters in survey areaReport significant shoaling via weekly progress reports. PM/COR may adjust prioritization based on observed shoaling.All waters in survey areaAcquire backscatter data during all multibeam data acquisition.Survey coverage was in accordance with the requirements listed above and in the HSSD.82.757350805627.4779247582.867738194427.6077272778The survey area is located in the Vicinity of Southwest Channel, in the general locality of the Approaches to Tampa Bay, Florida.The purpose of the project is to provide contemporary surveys to update National Ocean Service nautical charting products to support an increase in vessel traffic into Tampa Bay. There is a lack of modern data in the area and the area is subject to strong storm events that have the potential to cause shoaling.Survey limits were acquired in accordance with the requirements in the Project Instructions and the HSSD (2018).H13172 Survey LimitsSupportFiles\Fig1-H13172_Survey_Limits.pngOceaneeringApproaches to Tampa Bay, FLApproaches to Tampa Bay, FLOPR-J317-KR-18Contractor2018Scott MelanconSide Scan SonarMultibeam Echo Sounder2018-07-17metersThe 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/. Universal Transverse Mercator (UTM)UTCNavigable Area2018-10-172019-03-29Atlantic Hydrographic BranchFloridaH13172200003Vicinity of Southwest ChannelUnited StatesAll sounding systems were calibrated as detailed in the DAPR.All data reduction procedures conform to those detailed in the DAPR.MBESKongsberg MaritimeEM 3002SSSEdgeTech4200Positioning and Attitude SystemCodaOctopusF180Positioning SystemC-Nav3050Conductivity, Temperature, and Depth SensorSea-Bird ScientificSBE 19plusConductivity, Temperature, and Depth SensorYSI600R-BCR-C-TRefer 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.The R/V C-Wolf (Hull ID JQN00027J708) was used as the survey platform for all data acquisition within H13172.0.762JQN00027J7089.144noaa_custom.xml and CUBEParams.xmlV6005.0025Chesapeake TechnologySonarWiz1.7.6QPSQimeraQimera installs the standard NOAA custom attributes and are available by default to all users. The above referenced XML files are located within C:\Users\Public\Documents\QPS\Shared\Charts\Custom Attributes and C:\Users\Public\Documents\QPS\Resources, respectively. Qimera was used to process, clean and review all MBES data collected for H13172 as well as create all bathymetric surfaces. However, CARIS was still used for some review and evaluation procedures including: generating the final survey outline and obtaining area for the total SNM in Table 3, generation of the final SSS contact list and chart comparisons including LNM. In addition, a combination of Qimera and CARIS was used to generate the FFF. MBES Data ReviewThe data were filtered using a medium spline filter and surfaces examined systematically. The FlierFinder utility within HydrOffice QCTools was used as an additional quality control tool to evaluate the surfaces for fliers. Identified fliers were manually rejected. The least depths of contacts that met the threshold for designation (2 m x 2 m x 1 m) or were significant due to other distinguishing characteristics were set as 'custom hypotheses' in Qimera (and subsequently added to the FFF). This ensured the CUBE grid honored these least depths automatically upon updating the Dynamic Surface from edits. No additional finalization parameters were used. Features, both significant, insignificant and shoal soundings were also set as 'Features' to aid in the processing workflow. The fully cleaned CUBE surfaces were exported from Qimera as BAG files and appended with 'Final' as per the HSSD (2018) naming convention for MBES bathymetric surfaces.NOAA_1m16.340.33H13172_MB_1m_MLLW_FinalBAG1Complete MBESNOAA_0.5m12.4210.05H13172_MB_50cm_MLLW_1of2_FinalBAG0.5Object DetectionNOAA_0.5m9.944.15H13172_MB_50cm_MLLW_2of2_FinalBAG0.5Object DetectionN/AH13172_SSSAB_1m_545kHz_1of2SSS Mosaic1100% SSSN/AH13172_SSSAB_1m_545kHz_2of2SSS Mosaic1200% SSS0.82n/aJQN00027J708Surveyed soundings were reduced to MLLW using an ellipsoid separation model within the Qimera data processing software. The Total Propagated Uncertainty (TPU) for each sounding was computed within Qimera. No tide uncertainties were added for either a measured or zoning value. The vessel configuration editor within Qimera stores static values of the estimated uncertainties associated with each individual sensor. Internal verification indicates that the C-Nav™ 3050 systems have a vertical uncertainty of ~20 cm at the 95% confidence level. The 95% confidence level is expressed as 1.96 standard deviations from the mean. Qimera entries of uncertainty are assumed to be 1-sigma (one standard deviation from the mean) and this value of 20 cm is divided by 1.96 for a value of 10 cm to enter into Qimera. The 1-sigma VDATUM Maximum Combined Uncertainty (MCU) value for the separation model (13.1 cm) is provided in the project instructions. The vertical uncertainties associated with the positioning system and separation model were entered in the vessel editor and processing parameters editor, respectively, as shown in the DAPR. There are three places to enter uncertainty associated with the surface sound speed, which was entered in the transducer TPU location, as specified in the DAPR. The uncertainty associated with the measured CTD was entered within each individual sound velocity profile in the SVP Editor (Figure 6). An uncertainty layer is generated during the CUBE dynamic surface creation process that shows the uncertainty at each node of the surface. HydrOffice QCTools was used to analyze the uncertainty of the final exported BAG files, which contain depth and uncertainty information. Greater than 99% of nodes of the H13172_MB_1m_MLLW_Final surface meet specifications (Figure 7). Areas of higher uncertainty are generally associated with seafloor features and areas where overlapping data are separated by a time period at which the data indicate differences in seafloor bathymetry between time 1 and time 2; residual noise may also show higher uncertainty. Five nodes of the H13172_MB_50cm_MLLW_1of2_Final surface do not meet specifications (Figure 8), which are associated with a contact. All nodes of the H13172_MB_50cm_MLLW_2of2_Final surface meet specifications (Figure 9).Uncertainty associated with the measured CTD.SupportFiles\Fig6-H13172_SD_Sound_Speed.pngUncertainty QA output from HydrOffice QCTools for surface H13172_MB_1m_MLLW_Final.SupportFiles\Fig7-H13172_MB_1m_MLLW_Final.QAv5.tvu_qc.pngUncertainty QA output from HydrOffice QCTools for surface H13172_MB_50cm_MLLW_1of2_Final.SupportFiles\Fig8-H13172_MB_50cm_MLLW_1of2_Final.QAv5.tvu_qc.pngUncertainty QA output from HydrOffice QCTools for surface H13172_MB_50cm_MLLW_2of2_Final.SupportFiles\Fig9-H13172_MB_50cm_MLLW_2of2_Final.QAv5.tvu_qc.pngDensityThe Snapshot as Static Surface tool was used within Qimera to generate a Static Surface of the Bin Count (sounding density) layer of each final surface. The attached scalar (bin count) objects were exported as XYZ and further analyzed in either Microsoft Excel or a text editor, depending on the size of the file. It was observed that the density of the final surfaces meet the requirements for which at least 95% of all nodes on the surface shall be populated with at least 5 soundings. Histograms of the extracted sounding density surfaces were generated using Fledermaus (Figures 17 - 19). Very large density values of the H13172_MB_1m_MLLW_Final surface are associated with one area in particular where the vessel track is offline and the MBES appears to ping stationary for a short period of time (Figure 20). The acquisition logs indicate issues with a crab pot; the line was restarted just prior to where it left off.Histogram of the density layer of the H13172_MB_1m_MLLW_Final surface generated in Fledermaus.SupportFiles\Fig17-H13172_MB_1m_MLLW_Final_Density-1.pngHistogram of the density layer of the H13172_MB_50cm_MLLW_1of2_Final surface generated in Fledermaus.SupportFiles\Fig18-H13172_MB_50cm_MLLW_1of2_Final_Density.pngHistogram of the density layer of the H13172_MB_50cm_MLLW_2of2_Final surface generated in Fledermaus.SupportFiles\Fig19-H13172_MB_50cm_MLLW_2of2_Final_Density.pngArea of H13172_MB_1m_MLLW_Final surface where large density values exist.SupportFiles\Fig20-H13172_MB_1m_MLLW_Final_Density-2.pngHolidaysHydrOffice QCTools was used to determine the existence of holidays within all Object Detection MBES grids. No holidays exist within the H13172_MB_50cm_MLLW_1of2_Final surface. Two holidays exist within the H13172_MB_50cm_MLLW_2of2_Final surface, but both are outside the assigned radius. The main Complete Coverage surface was reviewed visually; MBES fill-ins were conducted when possible where along track data gaps existed. MBES data were acquired over all potentially significant contacts and visually inspected for coverage.Mainline coverage within the survey area consisted of Complete Coverage (100% side scan sonar with concurrent multibeam data) acquisition. Feature disprovals were conducted with either 200% SSS or Object Detection Multibeam Coverage. One assigned radius did not have a corresponding feature in the CSF file; this was reviewed with the PM (please refer to Supplemental Survey Records and Correspondence). Data do not indicate the presence of a contact in this location; no feature was added or removed in the FFF file. The one Fish Haven in the area was covered with Object Detection MBES coverage. Data coverage does not exist in the northeastern portion of the survey area where depths are shallower than 3.5 meters. Sonar SettingsIf necessary, the angle of the multibeam sonar was modified in order to moderate the effects of factors such as increased sea state or to increase coverage; any changes are documented in the acquisition logs. In addition, the MBES transducer was lowered and raised between two positions to mitigate the effects of sea state on data quality. This is noted in the logs and offsets updated in the MBES acquisition software during acquisition; no post-processing of any offsets occurred."W" Pattern ArtifactsThe data collected with the EM3002 multibeam echo sounder aboard the R/V C-Wolf (Hull ID JQN00027J708) exhibits a thicker region of nadir depth returns that manifests as an along track data artifact (Figure 14).H13172_MB_1m_MLLW_Final Surface with slice editor (3x exaggeration) showing the nadir region.SupportFiles\Fig14-H13172_Nadir_Artifact.png'Seesaw' Pattern ArtifactsNoise is evident in the MBES data periodically throughout the survey area. Particularly, artifacts are evident where one side of the swath gets shallower and one side gets deeper for a small period of time. Although it is unclear exactly the cause of this, field correspondence indicates it may be at least in part be due to aeration under the multibeam head. The noise is not systematic, which indicates it is due at least in part to environmental factors. These were most common on days 11-13-2018, 11-14-2018 and 11-18-2018 in the central-west portion of the survey area and cleaned as necessary, though this often left data gaps on either side of nadir (Figure 15).Port/starboard 'seesaw' artifact evident in MBES data.SupportFiles\Fig15-H13172_Artifact.pngMBES bottom detect in shallow areasIn the northeastern portion of the survey area the survey crew collected lines to determine the extent of the NALL. The multibeam system appeared to have difficulty detecting bottom in the shallowest portions of these lines. While the data were cleaned the bottom detect in this area may not be completely reliable (Figure 16). MBES bottom detect in shallow northeastern portion of the survey area.SupportFiles\Fig16-H13172_Shallow_Bottom_Detect.pngEnvironmental FactorsWeather, sea state, thermoclines, and fish/marine life were all temporary factors that affected the data periodically throughout the duration of the survey. These are noted in the acquisition and processing logs and reruns were collected when necessary.Sonar system quality control checks were conducted as detailed in the quality control section of the DAPR.Crosslines were generally run perpendicular to mainscheme lines in order for quality control statistics to be generated after completion of mainscheme survey lines. The total crossline mileage was 46.79 nautical miles and total mainline coverage was 871.90 nautical miles. Multibeam fill-ins are included in the total mainline mileage. Investigation lines and SSS rerun and fill-in lines for which MBES data were also acquired are not included. Separate 1-meter mainline and crossline Combined Uncertainty and Bathymetric Estimator (CUBE) surfaces were generated within Qimera and exported to BAG format. The BAG files were imported into Fledermaus and the surface difference tool used to evaluate crossline and mainscheme line agreement. The crossline surface was used as the reference surface and subtracted from the mainline surface using all data with no constraints. The difference surface was exported as an XYZ file and imported into Microsoft Excel for further review. Analysis indicates greater than 97% of difference values are between ±0.3 meters. This is well within the maximum allowable Total Vertical Uncertainty (TVU) for the depths of the comparison area of the mainline surface (0.41 – 16.34 meters), which ranges from ±0.50 to ±0.54 meters. It is evident from the histogram (Figure 3) that some depth differences exceed the maximum allowable TVU. Further examination indicates that depth differences greater than ±0.50 meters are concentrated within the north-central portion of the survey area (Figure 4). It is observed that the majority of the depth differences greater than ±0.50 meters are associated with mainlines collected in 2019 that overlap crosslines collected in 2018. In these areas data indicate that the seafloor is physically different between the mainline and crossline (Figure 5). The crossline and mainline BAG files, exported difference XYZ file and exported ASCII file of statistical results are located in Separates\II_Digital_Data\Crossline_Comparison.H13172 crossline comparison depth difference histogram from Fledermaus.SupportFiles\Fig3-H13172_Crossline_Comparison_1.pngH13172 survey area with crosslines in black and mainline data collected in 2019 in yellow. Purple squares indicate areas of overlap where differences are greater than ±0.50 meters.SupportFiles\Fig4-H13172_Crossline_Comparison_2.pngExample of difference between mainline 3156-1 and H72-TIE-303.SupportFiles\Fig5-H13172_Crossline_Comparison_3.pngSea-Bird Scientific SBE19 and SBE19plus Conductivity, Temperature, and Depth (CTD) sensors were used for speed of sound measurements through the water column. An Endeco YSI sonde was used to determine the sound speed at the transducer. The multibeam data were corrected for the water column sound speed in realtime using the SIS control software. Sound speed data are located in Separates II Digital Data\Sound Speed Data Summary.Once per day and more often if necessary.H131732018NOceaneering20000The survey junction between H13172 and H13173 will be addressed in the Descriptive Report for H13173. H131772018WOceaneering20000Sheet H13172 junctions with H13177 to the west. The overlap consists of mainlines and crosslines that extend into the adjoining survey. A difference surface was generated within Fledermaus between exported BAG files of the H13177_MB_1m_MLLW_Final and H13172_MB_1m_MLLW_Final surfaces with H13172 as the reference surface. All depth difference values range from ±0.61 meters with the majority between ±0.18 meters (Figure 11). All depth difference values are less than 2^0.5*TVU for the depths of the survey area; a depth of 0.5 meters has a maximum TVU of 0.5 meters and 2^0.5 * 0.5 meters is 0.707 meters. All depth difference values are less than 0.707 meters.Color bar showing the range of depth difference values between overlapping data of H13172 and H13177.SupportFiles\Fig11-H13172_H13177_Junction-1.pngW003122016NLiDAR20000Survey H13172 junctions with W00312 to the north. There is overlap of H13172 mainline and NALL investigation data with the W00312 junction survey as well as one assigned radius in which Object Detection MBES data was acquired for H13172. A difference surface was generated within Fledermaus between the W00312_LI_5m_MLLW_1of1 surface and a subset of the H13172 survey area covering the junction area gridded at 5-meters as the reference surface. The difference surface generated between the two surveys, in general, indicates that the depth data between the two surveys agree fairly well (Figure 12). However, it is evident that some difference values exceed the nominal 0.707-meter threshold specification. In order to determine the areas where the depth difference values are greater than 2^0.5*TVU the following steps were taken: An XYZ file of the H13172_MB_5m_MLLW surface was exported and a column of 2^0.5*TVU at the particular Z (depth) value generated (junction compliance). The difference surface between the H13172 and W00312 surfaces was also exported as XYZ and an absolute difference column created. The junction compliance (XYZ where Z is 2^0.5*TVU) and absolute difference (XYZ where Z is the absolute difference) files were imported into Fledermaus as gridded files. The absolute difference surface was subtracted from the junction compliance surface. Negative values indicate areas where the depth differences are greater than 2^0.5*TVU. The resulting surface was colored with one color representing positive values and one color representing negative values. There are three locations in particular where the depth difference values are greater than 2^0.5*TVU (Figure 13).Color bar showing the range of depth difference values between overlapping data of H13172 and W00312.SupportFiles\Fig12-H13172_W00312_Junction-1.pngOverlapping data from H13172 and W00312 overlain with the depth difference surface. Circles indicate areas where the depth difference values exceed 2^0.5*TVU. Yellow circles indicate areas where H13172 data are shallower than W00312 and red circle indicates area where H13172 data are deeper than W00312.SupportFiles\Fig13-H13172_W00312_Junction-2.pngSurvey H13172 junctions with two contemporary surveys and one historical survey: H13173, H13177 and W00312 (Figure 10). The surface difference tool within QPS' Fledermaus software was used to ensure general agreement of depths. Difference values greater than 2^0.5 * TVU, as outlined in the HSSD, were further evaluated.H13172 Survey JunctionsSupportFiles\Fig10-H13172_Survey_Junctions.pngRaw Backscatter was logged within the Kongsberg .all file and has been sent to the Processing Branch. Backscatter was not processed by the field unit.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 meet or exceed requirements as set forth in the NOS Hydrographic Surveys Specifications and Deliverables, Statement of Work and Project Instructions. 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.As Chief of Party, field operations for this hydrographic survey were conducted under my direct supervision, with frequent personal checks of progress and adequacy.Horizontal and Vertical Control Report2019-03-11Data Acquisition and Processing Report2019-05-29Chief of PartyScott Melancon2019-06-19GeoscientistNicole Galloway2019-06-19Additional information discussing the vertical or horizontal control for this survey can be found in the accompanying HVCR.Mean Lower Low WaterERS via VDATUMThe ellipsoid separation text file (TampaBay_EC_poly_xyNAD83-MLLW_geoid12b.txt) was gridded using Fledermaus with a cell size of 100 meters and saved as an SD file, which was applied in Qimera in Processing Parameters. TampaBay_EC_poly_xyNAD83-17N-MLLW_geoid12b.sdNorth American Datum 1983The positioning systems aboard the vessels utilize Oceaneering® C-Nav® systems which deliver Precise Point Positioning (PPP). The C-Nav® GPS systems receive corrections through the C-Nav® Subscription Services.Projected UTM 17