All data reduction procedures conform to those detailed in the DAPR.All sounding systems were calibrated as detailed in the DAPR.All equipment and survey methods were used as detailed in the DAPR. Backscatter was logged within each raw Kongsberg EM file.HydrOffice QCTools was used to analyze the density of all finalized surfaces. The density of all finalized surfaces meet the density requirements for which at least 95% of all nodes on the surface shall be populated with at least 5 soundings (Figures 28 – 36).DensitySupportFiles\Fig28-H13171_MB_1m_MLLW_Final_density.pngStatistical information about the density child layer of the H13171_MB_1m_MLLW_Final surface generated from HydrOffice QCTools.SupportFiles\Fig29-H13171_MB_50cm_MLLW_1of8_Final_density.pngStatistical information about the density child layer of the H13171_MB_50cm_MLLW_1of8_Final surface generated from HydrOffice QCTools.SupportFiles\Fig30-H13171_MB_50cm_MLLW_2of8_Final_density.pngStatistical information about the density child layer of the H13171_MB_50cm_MLLW_2of8_Final surface generated from HydrOffice QCTools.SupportFiles\Fig31-H13171_MB_50cm_MLLW_3of8_Final_density.pngStatistical information about the density child layer of the H13171_MB_50cm_MLLW_3of8_Final surface generated from HydrOffice QCTools.SupportFiles\Fig32-H13171_MB_50cm_MLLW_4of8_Final_density.pngStatistical information about the density child layer of the H13171_MB_50cm_MLLW_4of8_Final surface generated from HydrOffice QCTools.SupportFiles\Fig33-H13171_MB_50cm_MLLW_5of8_Final_density.pngStatistical information about the density child layer of the H13171_MB_50cm_MLLW_5of8_Final surface generated from HydrOffice QCTools.SupportFiles\Fig34-H13171_MB_50cm_MLLW_6of8_Final_density.pngStatistical information about the density child layer of the H13171_MB_50cm_MLLW_6of8_Final surface generated from HydrOffice QCTools.SupportFiles\Fig35-H13171_MB_50cm_MLLW_7of8_Final_density.pngStatistical information about the density child layer of the H13171_MB_50cm_MLLW_7of8_Final surface generated from HydrOffice QCTools.SupportFiles\Fig36-H13171_MB_50cm_MLLW_8of8_Final_density.pngStatistical information about the density child layer of the H13171_MB_50cm_MLLW_8of8_Final surface generated from HydrOffice QCTools.HydrOffice QCTools was used to determine the existence of holidays within all Object Detection Multibeam grids. No holidays exist within the Composite Source File (CSF) boundaries of the Fish Havens or user-delineated debris areas for the following grids: H13171_MB_50cm_MLLW_1of8_Final and H13171_MB_50cm_MLLW_2of8_Final. No holidays exist within the assigned radii for the following grids: H13171_MB_50cm_MLLW_3of8_Final, H13171_MB_50cm_MLLW_5of8_Final and H13171_MB_50cm_MLLW_6of8_Final Four holidays exist within the CSF boundary of the Fish Haven area and user-defined debris area of H13171_MB_50cm_MLLW_4of8_Final. Data indicate these are due to ‘acoustic shadows’ behind features. Five holidays exist within the user-defined debris area within H13171_MB_50cm_MLLW_7of8_Final. Data indicate these are due to gaps between lines and ‘acoustic shadows’ behind features. Three holidays exist within the assigned radii of the following grid: H13171_MB_50cm_MLLW_8of8_Final. Data indicate these are due to MBES ping drops. A small data gap exists between lines 2114.000 and 2114.001. This line was split in order to apply different GPS files to separate parts of the line.HolidaysSonar system quality control checks were conducted as detailed in the quality control section of the DAPR.Crosslines were run generally perpendicular to mainscheme lines in order for quality control statistics to be generated after completion of mainscheme survey lines. The total crossline mileage was 71.22 nautical miles and total mainline mileage was 1260.62 nautical miles. Multibeam fill-ins were included in the total mainline mileage. Investigation lines and SSS rerun lines for which MB was also acquired were not included. Separate 1-meter mainline and crossline Combined Uncertainty and Bathymetric Estimator (CUBE) surfaces were generated and the surface difference tool within CARIS HIPS was used to evaluate crossline and mainscheme line agreement. The mainline surface was used as Surface 1 and the crossline surface as Surface 2. Statistical information about the difference surface was generated using the Compute Statistics tool (Figure 3). The analysis shows that greater than 99% of depth difference values are between -0.24 and 0.26 meters. This is well within the maximum allowable Total Vertical Uncertainty (TVU) for the depths of the comparison area (6.69 – 18.08 meters) which ranges from ±0.508 to ±0.552 meters. It is evident from the histogram (Figure 3) that several depth differences exceed the maximum allowable TVU. Further examination indicates that depth differences greater than ±0.50 m are concentrated within 6 discrete areas (Figure 4) and associated with sea floor features/contacts. Review of these areas did not indicate obvious outliers. The crossline surface, mainline surface, difference surface and exported ASCII file of histogram results are located in Separates\II_Digital_Data\Crossline_Comparison.SupportFiles\Fig3-H13171_Crossline_Comparison.pngCrossline comparison statistics and histogram output from CARIS compute statistics tool.SupportFiles\Fig4-H13171_Crossline_Comparison-2.pngH13171 survey area overlain with crossline difference surface. Black sounding features within red polygons indicate areas where depth differences between mainline and crossline data are greater than ±0.50 m.If necessary, the angle of the multibeam sonars were 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.Sonar SettingsMultibeam data indicate an area of noise on line 2098 between timestamps 11:56:13 and 11:57:32 UTC that was difficult to clean.NoiseSections of data with a stretched appearance were noted in the SSS mosaic on line 2107 near timestamps 00:02:59 and 00:05:37 UTC. The project logs indicate that the navigation was lost in the collection software at new day. Further investigation indicates that this is a timing issue in that there is a time gap between consecutive pings. New navigation could not be inserted because there is no corresponding timestamp.NavigationSpiral artifacts were observed within the MBES data during post-processing (Figure 24). This appeared to occur after the original navigation had been replaced with processed GPS navigation. Further review indicated that the attitude and ellipsoid height appeared to look normal but the navigation (including ship speed) showed variation. An attempt was made to reject the navigation with interpolation within the MBES processing software (CARIS) which removed the spiral artifact but introduced a different artifact. Review of the post-processed, filtered GPS data indicated duplicate positions at consecutive times. The UNIX 'uniq' command was used to remove duplicate/repeating adjacent positions from the GPS files. Removing the duplicate positions and re-applying the new navigation (appended with .uniq) to the MBES data removed the spiral artifacts. This will become standard procedure for future surveys.Spiral ArtifactSupportFiles\Fig24-H13171_Spiral_Depth_Artifact.pngTop images show spiral depth artifact with post-processed ASCII navigation applied in both plan view (standard deviation layer) and 3D view. Bottom images show data processed with ASCII navigation after removing duplicate points in both plan view (standard deviation layer) and 3D view.Artifacts in which one side of the swath is deeper and one side is shallower for a small period of time were observed periodically throughout the survey (Figure 25). It is unclear exactly the cause of this; it could be a roll artifact or potentially due in part to aeration under the multibeam head. These were generally small and on the order of 10 cm from the surrounding sea floor. More extreme variations were cleaned as necessary.Seesaw Pattern ArtifactSupportFiles\Fig25-H13171_Seesaw_pattern_artifact.pngExample of artifact in which one side of the MBES swath is deeper and one side is shallower.Mainline coverage within the survey area consisted of Complete Coverage (100% side scan sonar with concurrent multibeam data acquisition). Feature disprovals as shown in the Project Reference File (PRF) were conducted with either 200% SSS or Object Detection Multibeam Coverage. Specifically, all Fish Haven Areas (including discrete obstructions with obstruction type as Fish Haven) were surveyed with Object Detection Multibeam coverage. Other assigned investigations were surveyed with either 200% SSS or Object Detection Multibeam (Figure 27). One feature did not have an assigned radius around it within the PRF. As per the original Project Instructions, a disproval radius of 480 meters was used. Water column data were collected over the Fish Haven areas with obvious debris and over all new investigation items. Bathymetric and water column data were acquired with a Kongsberg EM2040C multibeam echo sounder. Side scan sonar acoustic imagery was collected with a Klein 5000 V2 system. It was noted during post-processing that the Sheet bounds were not completely covered with SSS on much of the eastern side by up to several meters. It would appear that this was due in part to the line plan set up. The first line was close to 50 m from the edge of the sheet, so any amount of the vessel being offline could result in a data gap. Data in adjacent Sheet 1 (H13170) does cover the boundary and the data were included in the mosaic to ensure complete coverage within the survey bounds. SupportFiles\Fig27-H13171_Assigned_Investigation_Coverage.pngAssigned feature verification/disproval coverage within H13171.0.10.131ERS via VDATUMn/a0.812370942The Total Propagated Uncertainty (TPU) for each sounding was computed within CARIS, the multibeam data processing software. The vessel file stores static values of the estimated uncertainties associated with each individual sensor. The Compute TPU dialog contains placeholders for the user to specify tidal and sound speed uncertainty, as well as whether the sources of uncertainty are static (come from the vessel file) or were collected in real-time. This particular survey contains all static uncertainty sources. The above uncertainty estimates are combined with a DeviceModels.xml that contains individual sonar model characteristics to calculate the total TPU. Currently there is no entry for static vertical uncertainty associated with a positioning system or the separation model within CARIS. The workaround is to enter these values in the Tide Measured and Zoning entry locations. 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. CARIS 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 CARIS. The 1-sigma VDATUM Maximum Combined Uncertainty (MCU) value for the separation model (13.1 cm) is provided in the project instructions. An Uncertainty child layer is generated during the bathymetric surface creation process that shows the uncertainty at each node of the surface. HydrOffice QCTools was used to analyze the uncertainty of all finalized and un-finalized grids. It was observed that all uncertainty values are within specifications for all un-finalized surfaces (Figures 5 - 13). However, all but two of the finalized surfaces contain less than 0.002% of uncertainty values that do not meet specifications (Figures 14 - 22). Review indicates that this is due to the finalization parameter where the uncertainty is defined as the greater of either the standard deviation or uncertainty for a particular node. Review of the finalized surfaces indicates that nodes that do not meet specifications are associated with features and contacts.SupportFiles\Fig5-H13171_MB_1m_MLLW_tvu.pngUncertainty QA output from HydrOffice QCTools for surface H13171_MB_1m_MLLW.SupportFiles\Fig6-H13171_MB_50cm_MLLW_1of8_tvu.pngUncertainty QA output from HydrOffice QCTools for surface H13171_MB_50cm_MLLW_1of8.SupportFiles\Fig7-H13171_MB_50cm_MLLW_2of8_tvu.pngUncertainty QA output from HydrOffice QCTools for surface H13171_MB_50cm_MLLW_2of8.SupportFiles\Fig8-H13171_MB_50cm_MLLW_3of8_tvu.pngUncertainty QA output from HydrOffice QCTools for surface H13171_MB_50cm_MLLW_3of8.SupportFiles\Fig9-H13171_MB_50cm_MLLW_4of8_tvu.pngUncertainty QA output from HydrOffice QCTools for surface H13171_MB_50cm_MLLW_4of8.SupportFiles\Fig10-H13171_MB_50cm_MLLW_5of8_tvu.pngUncertainty QA output from HydrOffice QCTools for surface H13171_MB_50cm_MLLW_5of8.SupportFiles\Fig11-H13171_MB_50cm_MLLW_6of8_tvu.pngUncertainty QA output from HydrOffice QCTools for surface H13171_MB_50cm_MLLW_6of8.SupportFiles\Fig12-H13171_MB_50cm_MLLW_7of8_tvu.pngUncertainty QA output from HydrOffice QCTools for surface H13171_MB_50cm_MLLW_7of8.SupportFiles\Fig13-H13171_MB_50cm_MLLW_8of8_tvu.pngUncertainty QA output from HydrOffice QCTools for surface H13171_MB_50cm_MLLW_8of8.SupportFiles\Fig14_H13171_MB_1m_MLLW_Final_tvu.pngUncertainty QA output from HydrOffice QCTools for surface H13171_MB_1m_MLLW_Final.SupportFiles\Fig15-H13171_MB_50cm_MLLW_1of8_Final_tvu.pngUncertainty QA output from HydrOffice QCTools for surface H13171_MB_50cm_MLLW_1of8_Final.SupportFiles\Fig16-H13171_MB_50cm_MLLW_2of8_Final_tvu.pngUncertainty QA output from HydrOffice QCTools for surface H13171_MB_50cm_MLLW_2of8_Final.SupportFiles\Fig17-H13171_MB_50cm_MLLW_3of8_Final_tvu.pngUncertainty QA output from HydrOffice QCTools for surface H13171_MB_50cm_MLLW_3of8_Final.SupportFiles\Fig18-H13171_MB_50cm_MLLW_4of8_Final_tvu.pngUncertainty QA output from HydrOffice QCTools for surface H13171_MB_50cm_MLLW_4of8_Final.SupportFiles\Fig19-H13171_MB_50cm_MLLW_5of8_Final_tvu.pngUncertainty QA output from HydrOffice QCTools for surface H13171_MB_50cm_MLLW_5of8_Final.SupportFiles\Fig20-H13171_MB_50cm_MLLW_6of8_Final_tvu.pngUncertainty QA output from HydrOffice QCTools for surface H13171_MB_50cm_MLLW_6of8_Final.SupportFiles\Fig21-H13171_MB_50cm_MLLW_7of8_Final_tvu.pngUncertainty QA output from HydrOffice QCTools for surface H13171_MB_50cm_MLLW_7of8_Final.SupportFiles\Fig22-H13171_MB_50cm_MLLW_8of8_Final_tvu.pngUncertainty QA output from HydrOffice QCTools for surface H13171_MB_50cm_MLLW_8of8_Final.Weather, 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.Environmental FactorsSound speed artifacts were observed periodically within the data. Several lines on November 11, 2018 in particular show sound speed artifacts (Figure 26). Review indicates that lines collected with the previous day's CTD show more sound speed artifacts than the lines collected with the CTD nearest in time. The error was generally on the order of 10 cm and no additional sound speed correction other than what is specified in the DAPR was conducted during post-processing.Sound Speed ArtifactsSupportFiles\Fig26-H13171_Sound_Speed_Artifact.pngExample of sound speed artifacts within the H13171 MBES data. The navigation tracklines highlighted blue in the display window are lines from November 11, 2018. Exaggeration is set to 5x in the 2D display window.20000Oceaneering2018EH13170A preliminary junction comparison was conducted with H13170, which is located east of H13171. Preliminary analysis indicates greater that 99% of depth difference values are between -0.22 and 0.18 m. A thorough review will be completed in the Descriptive Report of H13170.20000Oceaneering2018SH13173The survey junction between H13171 and H13173 will be addressed in the Descriptive Report for H13173.20000Oceaneering2018WH13176The survey junction between H13171 and H13176 will be addressed in the Descriptive Report for H13176.Survey H13171 junctions with three contemporary surveys: H13170, H13173 and H13176 (Figure 23). A preliminary junction between H13171 and H13170 was conducted to ensure general agreement of depths. A difference surface between the depth layers of H13171 and the adjoining survey were generated and areas of disagreement were evaluated. A more thorough evaluation will be conducted in the specific Sheet Descriptive Reports using finalized surfaces when available that addresses difference values greater than 2^0.5 * TVU, as outlined in the HSSD (2018). SupportFiles\Fig23-H13171_Survey_Junctions.pngH13171 Survey Junctions.CTD casts were conducted twice per day and more often as necessary.Sea-Bird Scientific SBE19 and SBE19plus Conductivity, Temperature, Depth (CTD) sensors were used for speed of sound measurements through the water column. The water column sound speed profile was applied in Kongsberg's Seafloor Information System (SIS) MBES control software to correct the multibeam data in real-time. Endeco YSI sondes were used to determine the sound speed at the transducer. Sound speed data are located in Separates II Digital Data\Sound Speed Data Summary.NOAA Extended Attribute Files V5_8V6005.0025SonarWizChesapeake Technologies, Inc.CARIS HIPS version 10.4 was the primary software program used for bathymetric data processing. However, there was a period where there was an issue in CARIS with water column additional bathymetry not showing up in the right depth location. To continue moving forward, the water column data were reviewed in Qimera. Please note that although Table 11 states that Qimera was a primary program used for processing bathymetric data, it would be considered a secondary processing software. One S-57 of DtoNs 8 and 9 was also generated from Qimera during this time. The issue has since been fixed in CARIS. There was a zero entry in the SVC section of the vessel file that was causing the problem. This was removed and the MBES data re-merged in CARIS. A computer hardware issue prevented processing large amounts of water column data in CARIS and water column data were added sparingly. Water column data were added to additional bathymetry and the H13171_MB_1m_MLLW surface for investigations 17 and 19.10.4CARIS HIPSTeledyne1.7.4QimeraQPS1NOAA_1mH13171_MB_1m_MLLW18.086.17CARIS Raster Surface (CUBE)Complete MBES1NOAA_1mH13171_MB_1m_MLLW_Final18.085.70CARIS Raster Surface (CUBE)Complete MBES0.5NOAA_0.5mH13171_MB_50cm_MLLW_1of810.076.07CARIS Raster Surface (CUBE)Object Detection0.5NOAA_0.5mH13171_MB_50cm_MLLW_1of8_Final10.075.76CARIS Raster Surface (CUBE)Object Detection0.5NOAA_0.5mH13171_MB_50cm_MLLW_2of810.466.94CARIS Raster Surface (CUBE)Object Detection0.5NOAA_0.5mH13171_MB_50cm_MLLW_2of8_Final10.466.44CARIS Raster Surface (CUBE)Object Detection0.5NOAA_0.5mH13171_MB_50cm_MLLW_3of812.4411.24CARIS Raster Surface (CUBE)Object Detection0.5NOAA_0.5mH13171_MB_50cm_MLLW_3of8_Final12.4411.24CARIS Raster Surface (CUBE)Object Detection0.5NOAA_0.5mH13171_MB_50cm_MLLW_4of815.227.66CARIS Raster Surface (CUBE)Object Detection0.5NOAA_0.5mH13171_MB_50cm_MLLW_4of8_Final15.227.42CARIS Raster Surface (CUBE)Object Detection0.5NOAA_0.5mH13171_MB_50cm_MLLW_5of816.3114.24CARIS Raster Surface (CUBE)Object Detection0.5NOAA_0.5mH13171_MB_50cm_MLLW_5of8_Final16.3114.24CARIS Raster Surface (CUBE)Object Detection0.5NOAA_0.5mH13171_MB_50cm_MLLW_6of815.6113.67CARIS Raster Surface (CUBE)Object Detection0.5NOAA_0.5mH13171_MB_50cm_MLLW_6of8_Final15.6113.67CARIS Raster Surface (CUBE)Object Detection0.5NOAA_0.5mH13171_MB_50cm_MLLW_7of811.157.48CARIS Raster Surface (CUBE)Object Detection0.5NOAA_0.5mH13171_MB_50cm_MLLW_7of8_Final11.157.26CARIS Raster Surface (CUBE)Object Detection0.5NOAA_0.5mH13171_MB_50cm_MLLW_8of815.7613.23CARIS Raster Surface (CUBE)Object Detection0.5NOAA_0.5mH13171_MB_50cm_MLLW_8of8_Final15.7613.23CARIS Raster Surface (CUBE)Object Detection1N/AH13171_SSSAB_1m_455kHz_1of1SSS Mosaic100% SSS1N/AH13171_SSSAB_1m_455kHz_2of2SSS Mosaic200% SSSThe 'deep' and 'shoal' depth layers of the surfaces were reviewed to highlight outliers (fliers). Identified fliers were manually rejected. In addition, Bathymetric Attributed Grid (BAG) files of the 'deep' and 'shoal' layers were exported and HydrOffice QCTools Flier Detection utility used to identify potential fliers. These were imported into the CARIS display window and the data reviewed to further identify any potential erroneous MBES data, which were removed as necessary.MBES Data ReviewDuring post-processing, ASCII navigation files (time, lat, lon, GPS height) were imported into CARIS with an associated .info file, which contains information on the contents and formatting of the ASCII navigation files. When projects processed in the above manner were copied from a network location to external or internal drives or from internal to external drives it was observed that the path of the info file remained fixed to the original path name. Upon opening the copied project, the CARIS program asked to update the navigation folder, but not the info file. Keeping the info file in with the ASCII navigation did not appear to change this. Certain editors such as navigation editor or swath editor could not be opened within CARIS and the lines became locked. The workaround is to recreate the exact folder structure of the original project on the internal or external drive. However, it is recognized that this is an issue for submission because files are placed in the appropriate submission folders without regard for how the projects were originally set up. A request was logged with CARIS support and the information sent to the development team. Information from CARIS supports indicates that the Check Project process was not checking for an *.info file when using an ASCII file for auxiliary navigation. CARIS correspondence indicates that this has been fixed so that the check process will look for *.info missing files, enabling users to update their location using the Reset Raw Data Location dialog box. This fix should be available in both versions 10.4.10 (tentatively early-January) and 11.1.0 (tentatively mid-January). Due to licensing limitations this has not been tested in-house and the workaround to maintain original path names and drive letters was used. The original path for this project is: N:\noaa\2018-OPR-J317-KR-18_193519-TampaBay\Sheets\H13171-Sheet2\Geo\Software_Projects\CARIS\H13171Fixed File Path 40.841.981237094The R/V Sea Scout (Hull ID 1237094) was used as the survey platform for all data acquisition within H13171.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, and any deviations from the DAPR are discussed in the following sections.MBESEM 2040CKongsberg MaritimeSSS5000V2Klein Marine SystemsPositioning System3050C-NavAttitude SystemDMS05Teledyne TSSGyrocompassMeridian SurveyorTeledyne TSSConductivity, Temperature, and Depth SensorSBE 19plusSea-Bird ScientificConductivity, Temperature, and Depth Sensor600R-BCR-C-TYSIOPR-J317-KR-18Oceaneering International, Inc.Approaches to Tampa Bay, FLApproaches to Tampa Bay, FL20000FloridaH13171United States27 NM West of Long KeyUTC2018Navigable AreaAtlantic Hydrographic Branch2018-12-072018-09-29Side Scan SonarMultibeam Echo SounderAny 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.metersUniversal Transverse Mercator (UTM)Scott Melancon2018-07-17ContractorThe survey area is located 7 NM West of Long Key, in the general locality of the Approaches to Tampa Bay, Florida.SupportFiles\Fig1-H13171_Survey_Limits.pngThe H13171 survey limits shown as blue outline.27.61079282.86000627.80142883.039569All waters in survey area (except Sheet 4)Complete CoverageAll waters in survey areaReport significant shoaling via weekly progress reports. PM/COR may adjust survey prioritization based on observed shoaling.Survey coverage was in accordance with the requirements listed above and in the HSSD.The entire survey is adequate to supersede previous data.75.800022412018-09-292018-09-302018-10-012018-10-022018-10-032018-10-042018-10-052018-10-062018-10-132018-10-142018-10-152018-10-162018-10-172018-11-062018-11-072018-11-102018-11-172018-11-182018-11-192018-11-202018-11-232018-11-242018-12-062018-12-070.000.000.000.000.001260.620.0071.225.650.000.000.000.000.000.001260.620.0071.220.001237094It was observed that there were several unit options for nautical miles within the CARIS program. However, 'area' only had one option for nautical mile units as Square Int. Nautical Miles. To be consistent, Int. Nautical Miles was used as the unit for the LNM shown in Table 3. Detached Positions (DP) include CTD casts and lead line comparisons conducted within survey bounds, but not bottom samples because there is a separate entry for those.SupportFiles\Fig2-H13171_Survey_Coverage.pngH13171 Survey Coverage.Survey limits were acquired in accordance with the requirements in the Project Instructions and the HSSD.The purpose of the project is to provide contemporary surveys to update the National Ocean Service nautical charting products to support an increase in vessel traffic into Tampa Bay, FL. There is a lack of modern data in the area, which is subject to strong storm events that have the potential to cause shoaling.Prior to commencing survey operations, the Composite Source File indicated that seven charted wrecks, five fish haven areas and five discrete obstructions categorized as fish havens existed within survey bounds. One fish haven area feature on US5FL11M is shown as a discrete feature on US4FL10M (27.680°N, 82.928°W). This feature and one charted wreck (27.697°N, 82.946°W) have question mark symbols associated with them. One fish haven area is only partially covered by US5FL11M and is shown as two adjacent areas in the CSF file. These were all assigned to be investigated and either investigated with Object Detection Multibeam Coverage (fish haven areas in particular) or 200% side scan sonar coverage. Refer to the Final Feature File for additional information regarding all charted features.No Maritime Boundary Points were assigned for this survey.Twenty-two bottom samples were acquired within the bounds of H13171. It was recognized that this is one more than defined in the final Project Reference File (PRF). Review of field documents indicates that bottom samples 13 and 14 were shown to be almost right next to one another and further review indicates that the original PRF file received on June 11, 2018 shows two bottom samples in approximately the same location. The field inquired with OII Project Management and moved one of these bottom sample locations. Refer to the Final Feature File for additional information. Four additional obstructions were added to the Final Feature File that were not addressed as Dangers to Navigation either due to similarity to nearby charted depths or proximity to features with shallower leasts that were submitted as DtoNs. Refer to the Final Feature File for addtional information.Chart comparisons were evaluated in CARIS. A combination of sounding selection layers, user-defined depth ranges and contours generated from multibeam survey data were used to compare surveyed soundings to charted depths. The sounding selection layer was generated from the H13171 surface using a shoal biased, single-defined radius of 200 m, which provided sufficient soundings across the survey area with which to compare to charted depths and contours. In order to differentiate surveyed soundings, soundings from the selected sounding layer were separated into different layers based on charted contour depths: all soundings 9.1 m and less were added to one layer, soundings between 9.11 and 10.9 m were added to another layer, and soundings 10.91 m and greater were added to a final layer. The user defined depth range color chart based on charted contours is shown in Figure 37.SupportFiles\Fig37-Color_Range_Chart.pngColor range chart used to compare H13171 surveyed depths to charted contours.The survey area of H13171 partially covers two designated anchorages in the south and southwest portion of the survey area and partially covers the northern safety fairway for Egmont Channel in the southeast portion of the survey area. Comparison of the selected sounding layer and bathymetric surface and charted depths indicates that surveyed soundings generally agree with or are 0.3 - 0.6 m (1 - 2 ft) deeper than US5FL11M charted depths. US5FL11M shows two charted depths of 10 and 9.7 m (33 and 32 ft with NOAA rounding applied) as well as a small portion of the 9.1-m (29.86-ft) contour within with the overlap of the safety fairway and the H13171 survey area. Surveyed soundings generally agree with charted depths but are 0.4 m (~2 ft with NOAA rounding applied) shallower than the charted 10-m (33-ft) depth.Local Notice to Mariners (LNM) were downloaded from the Office of Coast Survey (OCS) website for Raster Nautical Chart (RNC) 11412 and reviewed subsequent to the date of the Project Instructions and before the end of the survey. The last LNM reviewed for Chart 11412 Current Edition 48 Print Date Jul./2018, Tampa Bay and St. Joseph Sound was LNM 45/18, 7th Dist posted on 11/15/2018 to Add an Obstruction in Feet. One Local Notice to Mariners was issued within the survey bounds (LNM 45/18, 7th Dist to Add Obstruction in Feet - 40 Obstn - posted on 11/1/2018) that corresponds to a DtoN submitted for this survey. US4FL10M is the only affected ENC that covers the entire bounds of survey H13171. Surveyed soundings range from 5.70 to 18.08 m (18.71 - 59.31 ft) referenced to MLLW and surveyed depths generally increase from the east and northeast to the west and southwest within the survey area. Review of the selected sounding layer and bathymetric surface indicates that surveyed soundings generally agree with charted depths within 0.3 m (1 ft), or surveyed soundings are deeper than charted depths by up to 1.2 m (4 ft). The 9.1-m (29.86-ft) and 10.9-m (35.76-ft) charted contours are present within the survey area. Survey data indicate that while depths of a particular range do exist within the presently charted contours, the outline and shape of the contours has changed. Data also indicate that several isolated contours no longer exist, while new isolated contours are present (Figures 38 - 41). SupportFiles\Fig38-US4FL10M_Chart_Comparison_1.pngImage of the northern section of the H13171_MB_1m_MLLW_Final surface colored using the depth range chart shown in Figure 37 with the 9.1-m US4FL10M charted contour shown in blue. Red soundings indicate soundings from the selected sounding layer that are 9.1 m or less. Yellow polygons indicate potentially new isolated contours. Black polygons show where survey data indicate deeper data is present than currently charted. Green polygons show examples of areas where the survey data indicate contours are similar but shifted.SupportFiles\Fig39-US4FL10M_Chart_Comparison_2.pngImage of the southern section of the H13171_MB_1m_MLLW_Final surface colored using the depth range chart shown in Figure 37 with the 9.1-m US4FL10M charted contour shown in blue. Red soundings indicate soundings from the selected sounding layer that are 9.1 m or less. Yellow polygons indicate potentially new isolated contours. Black polygons show where survey data indicate deeper data is present than currently charted. Green shows examples of areas where data indicate the contours are similar but shifted.SupportFiles\Fig40-US4FL10M_Chart_Comparison_3.pngImage of the northern section of the H13171_MB_1m_MLLW_Final surface colored using the depth range chart shown in Figure 37 with the 10.9-m US4FL10M charted contour shown in black. Green soundings indicate soundings from the selected sounding layer that are between 9.11 m and 10.9 m. Yellow polygons indicate potentially new isolated contours. Black polygons show where survey data indicate deeper data is present than currently charted. Green polygons show examples of areas where data indicate that the contours are have shifted.SupportFiles\Fig41-US4FL10M_Chart_Comparison_4.pngImage of the southern section of the H13171_MB_1m_MLLW_Final surface colored using the depth range chart shown in Figure 37 with the 10.9-m US4FL10M charted contour shown in black. Green soundings indicate soundings from the selected sounding layer that are between 9.11 m and 10.9 m. Black polygons show isolated contours where survey data indicate deeper data is present than currently charted. Green polygons show examples of areas where data indicate that the contours have shifted.800002018-12-10false2018-12-1032US4FL10MLocal Notice to Mariners (LNM) were downloaded from the OCS website for RNC 11415 and reviewed subsequent to the date of the Project Instructions and before the end of the survey. The last LNM reviewed for Chart 11415 Current Edition 13 Print Date Nov./2018, Tampa Bay Entrance; Manatee River Extension was LNM 45/18, 7th Dist posted on 11/15/2018 to Add an Obstruction in Feet. One Local Notice to Mariners was issued within the survey bounds (LNM 45/18, 7th Dist to Add Obstruction in Feet - 40 Obstn - posted on 11/1/2018) that corresponds to a DtoN submitted for this survey. US5FL11M covers all but the northwestern corner and northern peak of the H13171 survey area. The 9.1-m (29.86-ft) contours are present on US5FL11M within the survey area and although they vary slightly from the US4FL10M contour positions, the general trends and overall observations made for US4FL10M are valid for US5FL11M. There is one contour in the northeast portion of the survey area that is present on US5FL11M that is not present on US4FL10M (Figure 42). It is unclear if this contour should have a different value because, although it is labeled as a 9.1-m contour it is within a larger 9.1-m contour. Survey data indicate that depths are generally deeper than 9.1 m within this area. Depths on US5FL11M generally match those of US4FL10M though, due to the scale of the chart, more charted depths exist for USFL11M. Observations made for US4FL10M with regards to charted and surveyed depths are generally valid for US5FL11M. In three locations in particular (Figures 43 and 44), charted depths of US4FL10M are different than those of US5FL11M. SupportFiles\Fig42-US5FL11M_Chart_Comparison_1.pngImage of the southern section of the H13171_MB_1m_MLLW_Final surface colored using the depth range chart shown in Figure 37. Yellow outline shows one 9.1-m contour present on US5FL11M that is not present on US4FL10M. Survey data indicate that depths are generally deeper than 9.1 m in this area.SupportFiles\Fig43-US5FL11M_Chart_Comparison_2.pngImage of southwestern portion of H13171 survey area. Red soundings are from US5FL11M, grey soundings are from US4FL10M and black soundings are from the survey selected soundings layer. Black circle to the right shows a charted depth from US4FL10M that is not present on US5FL11M, but agrees with surveyed soundings. The left circle shows a charted depth from US4FL10M which is deeper than the US5FL11M charted depth in same area. Surveyed soundings show a variation of depths. SupportFiles\Fig44-US5FL11M_Chart_Comparison_3.pngImage of northwestern portion of H13171 survey area. Red soundings are from US5FL11M, grey soundings are from US4FL10M and black soundings are from the survey selected soundings layer. Black circle shows charted depth from US4FL10M, which is different from surrounding US5FL11M charted depths and deeper than surveyed soundings. 400002018-10-11false2018-12-1046US5FL11MUS5FL17M covers the very northern peak of the H13171 survey area. Charted depths and contours are similar to that of US4FL10M and observations made for US4FL10M are valid for USFL17M.400002018-12-03false2018-12-0313US5FL17MLocal Notice to Mariners (LNM) were downloaded from the OCS website for RNC 11400 and reviewed subsequent to the date of the Project Instructions and before the end of the survey. The last LNM reviewed for Chart 11400 Current Edition 36 Print Date Jan./2006, Tampa Bay to Cape San Blas was LNM 46/18, 8th Dist posted on 11/29/2018 to Add a Dangerous Wreck. One Local Notice to Mariners was issued within the survey bounds (LNM 45/18, 7th Dist to Add Obstruction in Fathoms - 6 1/2 Obstn - posted on 11/1/2018) that corresponds to a DtoN submitted for this survey. US3GC06M covers all but a narrow sliver in the southeast corner of the H13171 survey area. Because of the scale of the chart, the contours are much broader than those on US4FL10M (Figure 43). However, the general observations made for the US4FL10M chart are valid for US3G06M as well.SupportFiles\Fig45-US6GC06M_Chart_Comparison_1.pngImage of the H13171_MB_1m_MLLW_Final surface colored using the depth range chart shown in Figure 37 and red soundings from the selected sounding layer that are 9.1 m or less. Blue lines indicate the 9.1-m contour from US4FL10M and yellow lines indicate the 9.1-m contour from US3GC06M. 4563942018-05-23false2018-12-1023US3GC06MUS3GC07M covers a very small portion of the southeast corner of the H13171 survey area. The 5.40-m and 9.1-m (17.72-ft and 29.86-ft) contours extend slightly into the H13171 survey area but survey data indicate depths are deeper than 9.1 m (29.86 ft) in these areas.3500002018-06-14false2018-11-0533US3GC07MEleven potential Danger to Navigations were submitted within five separate DtoN Reports for this survey. Four discrete obstructions and two soundings within a larger debris area, which were originally part of DtoN #7, were accepted as official DtoNs. Refer to the Final Feature File and Supplemental Survey Records and Correspondence for additional information.No new insets are recommended for this area.No Aids to navigation (ATONs) exist for this survey.No prior survey comparisons exist for this survey.No ferry routes or terminals exist for this survey.No platforms exist for this survey.No present or planned construction or dredging exist within the survey limits.No abnormal seafloor and/or environmental conditions exist for this survey.No submarine features exist for this survey.No overhead features exist for this survey.No new surveys or further investigations are recommended for this area.Shoreline was not assigned in the Hydrographic Survey Project Instructions or Statement of Work.The 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.North American Datum 198317NMean Lower Low WaterTampaBay_EC_poly_xyNAD83-MLLW_geoid12bERS via VDATUMAdditional information discussing the vertical or horizontal control for this survey can be found in the accompanying HVCR.As Chief of Party, field operations for this hydrographic survey were conducted under my direct supervision, with frequent personal checks of progress and adequacy. 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.This report and attached survey data have been reviewed. This Descriptive Report, and all accompanying records and data are approved. All records are forwarded for final review and processing to the Processing Branch.2019-03-01Scott MelanconChief of Party2019-03-01Nicole GallowayGeoscientistData Acquisition and Processing Report2019-03-01Horizontal and Vertical Control Report2019-02-27