OPR-J317-KR-18Approaches to Tampa Bay, FLApproaches to Tampa Bay, FLOceaneering International, Inc.H131734Object Detection CoverageEgmont ChannelFloridaUnited States200002018Scott MelanconNavigable Area2018-07-172018-11-092019-07-21Multibeam Echo SounderMultibeam Echo Sounder BackscattermetersUniversal Transverse Mercator (UTM)UTCAtlantic Hydrographic BranchAny 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.ContractorThe survey area is located in the vicinity of Egmont Channel at the Approaches to Tampa Bay, Florida.27.65080883.04643927.50330482.754561H13173 Survey LimitsSupportFiles\Fig01_H73-SurveyLimits.pngSurvey limits were acquired in accordance with the requirements in the Project Instructions and the HSSD (2018).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, Florida. There is a lack of modern data in the area, which is subject to strong storm events that have the potential to cause shoaling.The entire survey is adequate to supersede previous data.Sheet 4Object Detection CoverageAll waters in survey areaReport significant shoaling via weekly progress reports. PM/COR may adjust survey prioritization based on observed shoaling.All waters in survey areaAcquire backscatter data during all multibeam data acquisition.Issues were recognized with respect to data collected with the EM2040C dual head configuration. For the majority of data collected in the dual head configuration, only one head acquired time series backscatter data; beam average backscatter data exists.H13173 Survey CoverageSupportFiles\Fig02_H73-SurveyCoverage.png12370940.00984.330.000.000.000.000.0055.190.00QN00027J7080.00480.860.000.000.000.000.0021.690.000.001465.190.000.000.000.000.0076.890.005.211092035.782019-11-092019-11-092019-02-272019-02-282019-03-012019-03-032019-03-072019-03-082018-03-092019-03-102019-03-112019-03-122019-03-142019-03-152019-03-162019-03-172019-03-232019-03-242019-03-252019-03-262019-03-292019-04-272019-04-282019-04-292019-04-302019-05-012019-05-022019-05-032019-05-042019-05-052019-05-062019-05-072019-05-082019-05-092019-05-112019-05-122019-05-132019-05-142019-05-152019-05-162019-05-172019-05-182019-05-192019-05-202019-05-212019-05-222019-05-242019-05-252019-05-262019-07-21It was observed that there were several unit options for nautical miles within the CARIS program. However, 'area' only had one option for the 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 fixes taken for CTD casts, lead line comparisons (if applicable) and buoys within survey bounds, but not bottom samples because there is a separate entry for those.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.123709440.841.98QN00027J7089.1440.762The R/V Sea Scout (Hull ID 1237094) and R/V C-Wolf (Hull ID JQN00027J708) were used as the survey platforms for data acquisition within H13173.Kongsberg MaritimeEM 2040CMBESKongsberg MaritimeEM 3002MBESC-Nav3050Positioning SystemCodaOctopusF180Positioning and Attitude SystemTeledyne TSSDMS05Attitude SystemTeledyne TSSMeridian SurveyorGyrocompassSea-Bird ScientificSBE 19Conductivity, Temperature, and Depth SensorSea-Bird ScientificSBE 19plusConductivity, Temperature, and Depth SensorYSI600R-BCR-C-TConductivity, Temperature, and Depth SensorCrosslines were run generally perpendicular to main scheme survey lines in order for quality control statistics to be generated after completion of main scheme lines. The total crossline mileage was 76.89 LNM and the total mainline mileage was 1465.19 LNM. Multibeam fill-ins were included in the total mainline mileage but lines collected specifically for investigation purposes were not included. Separate 50-cm 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 main scheme line agreement. The mainline surface was used as Input A and the crossline surface as Input B. 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 -0.32 and 0.28 meters. This is well within the maximum allowable Total Vertical Uncertainty (TVU) for the depths of the comparison area of the mainline surface (2.64 – 28.54 meters), which ranges from ±0.501 to ±0.623 meters. It is evident from the histogram (Figure 3) that several depth difference values exceed the maximum allowable TVU. Difference values greater than the maximum TVU were addressed using the following methodology. An absolute difference layer for the mainline/crossline difference surface was created by squaring all difference values and then taking the square root of those values. A maximum TVU layer was generated for the H13173_MB_MLLW_50cm_Mainlines surface using the following formula: (0.5^2+(0.013*Depth)^2)^0.5. The absolute difference layer was subtracted from the maximum TVU layer. Positive values indicate that the difference between the mainline and crossline data sets are less than the maximum TVU while negative values indicate that the difference between the two data sets are greater than the maximum TVU. Areas of disagreement were evaluated. Correspondence with CARIS indicates a known issue with the Compute Layer tool in CARIS 10.4. When Depth is in the middle of an expression, the Compute Layer function assumes Depth is negative even if Z-axis convention is set to positive. It was observed that the signs of computed layers in CARIS were not consistent in CARIS 10.4 and all junction analyses were conducted using CARIS 9.1. Further examination indicates depth differences greater than the maximum TVU (Figure 4) are generally associated with sea floor features with a more notable exception in the central portion of the survey area. Refer to section B.2.5 for additional information. The crossline surface, mainline surface, difference surface and exported ASCII file of histogram results are located in Separates\II_Digital_Data\Crossline_Comparison.H13173 crossline comparison statistics and histogram output from CARIS compute statistics tool.SupportFiles\Fig03_H73-CrosslineComparison-1.pngH13173 survey area overlain with black compass features that indicate where depth difference values between mainlines and crosslines are greater than the maximum TVU.SupportFiles\Fig04_H73-CrosslineComparison-2.png0.10.131ERS via VDATUM12370942n/a0.8JQN00027J7082n/a0.8The Total Propagated Uncertainty (TPU) for each sounding was computed within CARIS, the MBES 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 a separation model within CARIS. The workaround is to enter these values in the Tide Measured and Zoning entry locations. Internal verification indicates 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 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 and (Figures 5-6) but the finalized surfaces contain less than 0.1% of values that do not meet specifications (Figures 7-8). Review indicates 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. The majority of nodes that do not meet specifications are associated with seafloor features, contacts, changes in bathymetry and along areas where data indicate evidence of potential sound speed artifacts and/or erroneous data points. The areas with a potential artifact and/or erroneous data points do not appear to contribute substantially to the overall surface depth value as reviewed in subset editor with the reference surface loaded, but appear to still contribute to the overall standard deviation.Uncertainty QA output from HydrOffice QCTools for surface H13173_MB_50cm_MLLW.SupportFiles\Fig05_H73_MB_50cm_MLLW.QAv5.tvu_qc.pngUncertainty QA output from HydrOffice QCTools for surface H13173_MB_1m_MLLW.SupportFiles\Fig06_H73_MB_1m_MLLW.QAv5.tvu_qc.pngUncertainty QA output from HydrOffice QCTools for surface H13173_MB_50cm_MLLW_Final.SupportFiles\Fig07_H3_MB_50cm_MLLW_Final.QAv5.tvu_qc.pngUncertainty QA output from HydrOffice QCTools for surface H13173_MB_1m_MLLW_Final.SupportFiles\Fig08_H73_MB_1m_MLLW_Final.QAv5.tvu_qc.pngH13173 junctions with six contemporary surveys (H13170, H13171, H13172, H13176, H13177 and H13178) and one prior survey (W00312) as shown in Figure 9. Difference surfaces between the depth layers of 1-meter resolution surfaces for H13173 and the adjoining surveys were generated and areas of disagreement were evaluated. Finalized surfaces were used when available. The analysis addresses difference values greater than 2^0.5 * TVU, as outlined in the HSSD (2018). The minimum depth for the H13173 survey area is 2.57 meters with a TVU of ±0.501 meters and 2^0.5 * TVU of ±0.709 meters. Depth difference values greater than 2^0.5 meters would need to at least exceed ±0.709 meters. Difference values greater than 2^0.5 * TVU were addressed using the following methodology. An absolute difference layer for each junction difference surface was created by squaring all difference values and then taking the square root of those values. A junction compliance layer was generated for the H13173_MB_MLLW_1m surface using the following formula: 2^0.5 * TVU where TVU is (0.5^2+(0.013*Depth)^2)^0.5, as outlined in section 8.1.4 of the HSSD (2018). The absolute difference layer was subtracted from the junction compliance layer. Positive values indicate the difference between the two data sets is less than 2^0.5 * TVU while negative values indicate the difference between the two data sets is greater than 2^0.5 * TVU. Areas of disagreement were evaluated. Correspondence with CARIS indicates a known issue with the Compute Layer tool in CARIS 10.4. When Depth is in the middle of an expression, the Compute Layer function assumes Depth is negative even if Z-axis convention is set to positive. It was observed that the signs of computed layers in CARIS were not consistent in CARIS 10.4 and all junction analyses were conducted using CARIS 9.1.H13173 Survey JunctionsSupportFiles\Fig09_H73-SurveyJunctions.pngW00312200002016LiDARESheet H13173 junctions with W00312 to the east. A 5-meter grid of the eastern portion of H13173 was used for comparison. This junction is located at the mouth of the Egmont Channel. The difference surface shows large discrepancies between the two surfaces with only 50% of soundings falling between -0.435 and 0.465 meters. Depths from H13173 are generally deeper along the northern boundary and shallower along the southern boundary. Along the northern boundary one area indicates differences up to 7 meters, with H13173 data being deeper (blue box Figure 11).Histogram of depth difference values between overlapping data of H13173 and W00312.SupportFiles\Fig10_H73JunctionW00312-1.pngDepth difference surface between H13173 and W00312. Blue box shows area where differences are up to 7 meters.SupportFiles\Fig11_H73JunctionW00312-2.pngH13170200002018OceaneeringNH13173 junctions with H13170 to the north. The overlap consists of mainlines and crosslines that extend into the adjoining sheet. A difference surface was generated between the two surveys with H13173_MB_1m_MLLW as Input A and H13170_MB_1m_MLLW_Final as Input B. The difference surface indicates over 99% of nodes are within ±40 cm (Figure 12). Figure 13 shows the nodes where differences are greater than 2^0.5 *TVU. These are areas of bathymetric change and review of the surfaces indicates features are different from one data set to the other.Histogram of depth difference values between overlapping data of H13173 and H13170.SupportFiles\Fig12_H73JunctionH70-1.pngOverlap of H13173 and H13170 with cartographic symbols indicating nodes that exceed the 2^0.5 * TVU threshold.SupportFiles\Fig13_H73JunctionH70-2.pngH13171200002018OceaneeringNH13173 junctions with H13171 to the north. The overlap consists of mainlines and crosslines that extend into the adjoining sheet. A difference surface was generated between the two surveys with H13173_MB_1m_MLLW as Input A and H13171_MB_1m_MLLW_Final as Input B. The difference surface indicates over 99% of nodes are within ±35 cm (Figure 14). All depth difference values are less than 2^0.5 * TVU.Histogram of depth difference values between overlapping data of H13173 and H13171.SupportFiles\Fig14_H73JunctionH71-1.pngH13172200002018OceaneeringSH13173 junctions with H13172 to the south. The overlap consists of mainlines and crosslines that extend into the adjoining sheet. A difference surface was generated between the two surveys with H13173_MB_1m_MLLW as Input A and H13172_MB_1m_MLLW_Final as Input B. Over 99% of nodes are between -0.26 and 0.24 meters (Figure 15). All depth difference values are less than 2^0.5 * TVU.Histogram of depth difference values between overlapping data of H13173 and H13172.SupportFiles\Fig15_H73JunctionH72-1.pngH13176200002018OceaneeringWH13173 junctions with H13176 to the west. The overlap consists of mainlines and crosslines that extend into the adjoining sheet. A difference surface was generated between the two surveys with H13173_MB_1m_MLLW as Input A and H13176_MB_1m_MLLW as Input B. Over 99% of nodes are within -0.19 to 0.21 meters (Figure 16). The difference value of one node is greater than 2^0.5 * TVU (Figure 17). This node is on the edge of a bathymetric feature and may represent a positional offset between the two data sets.Histogram of depth difference values between overlapping data of H13173 and H13176.SupportFiles\Fig16_H73JunctionH76-1.pngOverlap of H13173 and H13176 with cartographic symbol indicating node that exceeds the 2^05 * TVU threshold.SupportFiles\Fig17_H73JunctionH76-2.pngH13177200002018OceaneeringSH13177 junctions with H13177 to the south and southwest. The overlap consists of mainlines and crosslines that extend into the adjoining sheet. A difference surface was generated between the two surveys with H13173_MB_1m_MLLW as Input A and H13177_MB_1m_MLLW_Final as Input B. Over 99% of nodes are within -0.28 and 0.32 meters (Figure 18). All depth difference values are less than 2^0.5 * TVU.Histogram of depth difference values between overlapping data of H13173 and H13177.SupportFiles\Fig18_H73JunctionH77-1.pngH13178400002018OceaneeringSWThe survey junction between H13173 and H13178 will be addressed in the Descriptive Report for H13178.Sonar system quality control checks were conducted as detailed in the quality control section of the DAPR.Sonar SettingsIf 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. Aboard the R/V Sea Scout, data were collected with a combination of a dual head EM2040C and single head EM2040C MBES system in a dual head configuration after issues with the system prevented both heads from being operational. Although it was attempted to run both heads as much as possible, fill-ins were conducted as necessary when gaps in coverage 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 19). This is more noticeable in the higher resolution, 50-cm grids. Although individual soundings can deviate up to one meter, the surface does not honor these deep soundings."W" pattern artifact evident in data collected aboard the R/V C-Wolf.SupportFiles\Fig19_H73-CwolfData.pngMotion Artifacts, Ping Drops and Vertical OffsetsMinor motion artifacts on the outer swath (Figure 20) and ping drops (Figure 21) were evident periodically throughout the data collected with the R/V Sea Scout; if overlapping data did not exist, fill-ins were collected. In addition, some vertical offsets exist in the data. These appear to generally occur on lines that exhibit a curve, but one line in particular shows an offset (Figure 22). The cause is not readily evident, though the project acquisition logs indicate this was the last line run before the decision was made to attempt north/south lines due to weather conditions. The vertical difference is within the maximum allowable TVU and no additional post-processing of this line was conducted.Motion artifacts within data collected with the R/V Sea Scout.SupportFiles\Fig20_H73-SeaScoutData-1.pngPing drops within data collected with the R/V Sea Scout.SupportFiles\Fig21_H73-SeaScoutData-2.pngVertical offset of line 4347 within R/V Sea Scout data.SupportFiles\Fig22_H73-SeaScoutData-3.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.Twice per day and more often as necessary aboard the R/V Sea Scout and once per day and more often if necessary aboard the R/V C-Wolf.Sea-Bird Scientific SBE19 and SBE19plus Conductivity, Temperature, and Depth (CTD) sensors were used for speed of sound measurements through the water column. Endeco YSI sondes were used to determine the sound speed at the transducer. The multibeam data were corrected for the water column sound speed in real-time using the SIS control software. Sound speed data are located in Separates\II_Digital_Data\Sound_Speed_Data_Summary.Coverage within the survey area consisted of Object Detection MBES data acquisition. Bathymetric data were acquired with a combination of a single head Kongsberg EM3002 MBES system (aboard the R/V C-Wolf) and dual head and single-head Kongsberg EM2040C MBES systems (aboard the R/V Sea Scout). DensityHydrOffice QCTools was used to analyze the density of all finalized surfaces. The density of all finalized surfaces meets the density requirements for which at least 95% of all nodes on the surface shall be populated with at least 5 soundings (Figures 23-24).Statistical information about the density child layer of the H13173_MB_50cm_MLLW_Final surface.SupportFiles\Fig23_H73_MB_50cm_MLLW_Final.QAv5.density.pngStatistical information about the density child layer of the H13173_MB_1m_MLLW_Final surface.SupportFiles\Fig24_H73_MB_1m_MLLW_Final.QAv5.density.pngHolidaysHydrOffice QCTools was used to determine the existence of holidays within all finalized Object Detection MBES grids. The results show over 1000 holidays within the H13173_MB_1m_MLLW_Final surface within survey bounds. Review of this surface indicates these holidays are due to the depth threshold applied during the finalization process. Review of the 1-meter un-finalized surface does not indicate any holidays within survey bounds. The HydrOffice QCTools results also indicate over 100 holidays within the H13173_MB_50cm_MLLW_Final surface within survey bounds. Review of this surface indicates this is mainly due to the depth threshold applied during the finalization process, but three holidays do exist that are not a function of the depth threshold applied during the finalization process, but appear to be due to rejecting noisy data. Review of holidays within the 50-cm un-finalized surface indicates only the three aforementioned holidays within survey bounds. The field crew has since left the survey site and these could not be filled in.All data reduction procedures conform to those detailed in the DAPR.All sounding systems were calibrated as detailed in the DAPR.Raw backscatter data were logged within the Kongsberg .all file and has been sent to the Processing Branch. An issue was recognized with respect to the dual head configuration in that for the majority of the data collected with the EM2040C dual head, only one head acquired time series backscatter data; beam average backscatter data exist.CarisHIPS/SIPS10.4NOAA Profile V_5_8H13173_MB_50cm_MLLWCARIS Raster Surface (CUBE)0.52.5228.54NOAA_0.5mObject DetectionH13173_MB_50cm_MLLW_FinalCARIS Raster Surface (CUBE)0.52.4920.00NOAA_0.5mObject DetectionH13173_MB_1m_MLLWCARIS Raster Surface (CUBE)12.5728.41NOAA_1mObject DetectionH13173_MB_1m_MLLW_FinalCARIS Raster Surface (CUBE)118.0028.41NOAA_1mObject DetectionMBES Data ReviewIt was recognized that the CARIS project indicated 6 lines collected with the R/V Sea Scout (4300, 4345, 4346, 4247, 4350 and TIE-427) had a tide file loaded during processing. The CARIS processing log indicates the tide file was loaded after the GPS tide was computed. These 6 lines were reprocessed (Load ASCII Navigation > Compute GPS tide > Merge) to ensure GPS tide was applied even though the CARIS log will still note the presence of a tide file. Surface filters were attempted, but it was decided to re-accept the filtered data due to more data than the processor was comfortable with being rejected. The data were manually reviewed for outliers (fliers) using the standard deviation and depth layers. Higher standard deviation is generally associated with bathymetric features, contacts and/or areas of bathymetric change. Noise can also be identified by high standard deviation. The Flier Finder utility within HydrOffice QCTools was used as an additional quality control tool to evaluate the surface for fliers. Identified fliers were manually rejected. A final check on the H13173_MB_50cm_MLLW_Final and H13173_MB_1m_MLLW_Final surfaces was conducted using HydrOffice QCTools 2 v2.7.0 Flier Finder with the default parameters selected. The results indicate a total of 73 potential fliers within survey bounds for the H13173_MB_50cm_MLLW_Final surface. Twenty-seven are flagged as flier finder flag 1 (Laplacian Operator), which are all associated with designated soundings. Forty-five are flagged as flier finder flag 5 (isolated nodes) and one is flagged as flier finder flag 6 (noisy edges), which appear associated with the depth threshold applied during the surface finalization process. The results indicate a total of 301 potential fliers within survey bounds for the H13173_MB_1m_MLLW_Final surface with 20 nodes flagged as flier finder flag 6 (noisy edges) and the remaining 281 nodes flagged as flier finder flag '5' (isolated nodes); these all appear associated with the depth parameter threshold applied during the surface finalization process. Fixed File PathDuring 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 support 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 and 11.1.0. 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\H13173-Sheet4\Geo\Software_Projects\CARIS. Additional information discussing the vertical or horizontal control for this survey can be found in the accompanying HVCR.Mean Lower Low WaterERS via VDATUMTampaBay_EC_poly_xyNAD83-MLLW_geoid12bNorth American Datum 1983Projected UTM 17The positioning systems aboard the vessels utilize Oceaneering C-Nav systems which deliver Precise Point Positioning (PPP). The C-Nav GPS receives corrections through the C-Nav Subscription Services.A combination of sounding selection layers and user-defined depth ranges, if applicable, were used to compare surveyed soundings to charted depths using tools within the CARIS MBES data processing software. Figure 25 shows the color range that was used in the chart comparison images. Surveyed depths of the un-finalized 50-cm surface range from 2.52 - 28.54 meters with the shallowest depths on either side of the dredged portion of Egmont Channel and the deepest depths within the channel in the far east portion of the survey area.Color range chart used in chart comparisons.SupportFiles\Fig25_ChartComparison-Colormap.pngUS4FL10M80000342019-03-182019-07-30falseNOAA Local Notice to Mariners (LNM) were reviewed for Chart: 11412, Current Edition: 49, Print Date: Feb. /2019, Tampa Bay and St. Joseph Sound subsequent to the data of the Project Instructions and before the end of the survey. The last LNM reviewed was LNM 27/19, 7th Dist to Add a Sounding in Feet posted on 06/27/2019. Four LNM were issued within survey bounds subsequent to the date of the Project Instructions and before the end of the survey. Two were issued to Change Egmont Channel Lighted Buoy 4 (LNM 11/19 and LNM 22/19, posted 3/21/2019 and 6/13/2019, respectively) and two were issued to Change Egmont Channel Lighted Buoy 6 (LNM 11/19 and LNM 15/19, posted 3/21/2019 and 4/25/2019). This chart covers all but the furthest west part of the survey area. The eastern portion of the Egmont Channel is difficult to compare due to the changes in depth, so this comparison will look at the charted contours as the primary comparison. There are two areas where H13173 survey depths shallower than 3.6 meters extend beyond the charted contour (Figure 26). The same areas of shoaling have affected the charted 5.4-meter contour, with depths as little as 2.6 meters going beyond the contour in the larger area to the west (Figure 27). In Figure 28, red indicates areas where depths shallower than 9.1 meters extend beyond the charted contour and Figure 29 indicates areas where depths shallower than 10.9 meters extend beyond the charted contour. Like the 9.1-meter contour, the discrepancy between the chart and surveyed depths is less drastic than what was seen with the 3.6 and 5.4-meter contours. Other than the areas pointed out in Figures 26 - 29, depths in the far eastern area of the survey area are deeper than charted. Moving west through the survey area, surveyed depths are generally within a meter of charted. There are dumping grounds along the southern edge of the survey area, and while survey data indicate some of the dumped material exists outside of the designated zones, depths remain in line with the chart (Figure 30 with charted soundings black against the surveyed soundings). Throughout the rest of the survey area, surveyed depths agree to within a meter of charted depths. In the west and southwest portions of the survey area is it evident surveyed depths deeper than 18.2 meters extend shoreward of the currently charted contours. There are, however, some areas where depths surveyed depths are shallower than charted. Figure 31 shows areas in green that indicate where depths shallower than 10.9 meters have extended beyond the charted 10.9-meter contours.Areas where surveyed depths shallower than 3.6 meters extend beyond the charted contour.SupportFiles\Fig26_H73-ChartComparison-US4FL10M-1.pngAreas where surveyed depths shallower than 5.4 meters extend beyond the charted contour.SupportFiles\Fig27_H73-ChartComparison-US4FL10M-2.pngAreas where surveyed depths shallower than 9.1 meters extend beyond the charted contour.SupportFiles\Fig28_H73-ChartComparison-US4FL10M-3.pngAreas where surveyed depths shallower than 10.9 meters extend beyond the charted contour.SupportFiles\Fig29_H73-ChartComparison-US4FL10M-4.pngComparison of central survey area to charted depths and contours.SupportFiles\Fig30_H73-ChartComparison-US4FL10M-5.pngAreas in green indicate where depths shallower than 10.9 meters have extended beyond the charted 10.9 meter contours.SupportFiles\Fig31_H73-ChartComparison-US4FL10M-6.pngUS5FL11M40000472019-03-112019-07-16falseNOAA Local Notice to Mariners (LNM) were reviewed for Chart: 11415, Current Edition: 13, Print Date: Nov. /2018, Tampa Bay Entrance; Manatee River Extension subsequent to the date of the Project Instructions and before the end of the survey. The last LNM reviewed was LNM 30/19, 7th Dist to Add an Obstruction in Feet posted on 07/18/2019. Four LNM were issued within survey bounds subsequent to the date of the Project Instructions and before the end of the survey. Two were issued to Change Egmont Channel Lighted Buoy 4 (LNM 11/19 and LNM 22/19, posted 3/21/2019 and 6/13/2019, respectively) and two were issued to Change Egmont Channel Lighted Buoy 6 (LNM 11/19 and LNM 15/19, posted 3/21/2019 and 4/25/2019). Compared to chart US4FL10M, the charted contours are not quite in the same position and the 10.9-meter contour is not present, but the general trend of comparison is the same. Figure 32 displays an area where surveyed soundings shallower than 3.6 meters extend beyond the charted 3.6-meter contour. In this same area, depths as little as 2.6 meters go beyond the 5.4-meter contour as well. Figure 33 shows the full extents of surveyed soundings shallower than 5.4 meters that extend beyond the charted 5.4-meter contour. Figure 34 indicates where depths are up to a meter shallower than the charted 9.1-meter contour. Throughout the rest of the survey area, including the dumping grounds, surveyed depths generally agree to within 1-meter of charted soundings. There are several areas where survey data is deeper by over a meter, but no areas that indicate substantial shoaling in the western portion of the survey area.Depths shallower than 3.6 meters extend beyond the 3.6-meter contour.SupportFiles\Fig32_H73-ChartComparison-US5FL11M-1.pngFull extents of surveyed soundings shallower than 5.4 meters extend beyond the charted 5.4-meter contour.SupportFiles\Fig33_H73-ChartComparison-US5FL11M-2.pngDepths up to a meter shallower than the charted 9.1-meter contour.SupportFiles\Fig34_H73-ChartComparison-US5FL11M-3.pngUS3GC07M350000342019-03-112019-07-12falseNOAA Local Notice to Mariners (LNM) for Chart: 11420, Current Edition: 32, Print Date: Oct. /2018, Havana to Tampa Bay were reviewed subsequent to the date of the Project Instructions and before the end of the survey. The last LNM reviewed was LNM 30/19, 7th Dist to Add an Obstruction in Fathoms posted on 7/18/2019. No LNM were issued within the survey area subsequent to the date of the Project Instructions and before the end of the survey. This chart covers all but the northernmost part of the survey area. In the southwest part of the survey area, there are two charted soundings, and both are 1 to 2 meters shallower than surveyed soundings (Figure 35). Figure 36 shows the charted 9.1 and 5.4-meter contours. Surveyed depths in this area are deeper than the 9.1-meter contours by up to 3 meters, and deeper than the 5.4 meter contour by nearly 5 meters. In the easternmost part of the survey area, there are 6.8 and 13.7-meter charted depths. Figure 37 shows that surveyed soundings are deeper than these charted depths by up to 2 meters. There are a number of soundings in the survey area that are associated with charted obstructions. These will be addressed in the Final Feature File.Comparison of surveyed soundings and US3GC07M charted depths in the southwest portion of the survey area.SupportFiles\Fig35_H73-ChartComparison-US3GC07M-1.pngComparison of surveyed soundings and US3GC07M charted contours in the central portion of the survey area.SupportFiles\Fig36_H73-ChartComparison-US3GC07M-2.pngComparison of surveyed soundings and US3GC07M charted depths in the eastern portion of the survey area.SupportFiles\Fig37_H73-ChartComparison-US3GC07M-3.pngUS3GC06M456394242019-03-122019-06-10falseNOAA Local Notice to Mariners (LNM) for Chart: 11400, Current Edition: 37, Print Date: Apr. /2019, Tampa Bay to Cape San Blas were reviewed subsequent to the date of the Project Instructions and before the end of the survey. The last LNM reviewed was LNM 30/19, 7th Dist to Add an Obstruction in Fathoms posted on 7/18/2019. No LNM were issued within the survey area subsequent to the date of the Project Instructions and before the end of the survey. This chart covers only a slice of the survey area to the north. Figure 38 shows surveyed depths are at least 1-meter deeper than the two charted depths in the western part of this slice. The 11.8-meter obstruction will be addressed in the final feature file. Moving east, portions of the 9.1 and 5.4-meter contours are present within the survey area. Depths greater than 9.1 meters are present within the charted contour. Surveyed soundings greater than 5.4-meters are observed to extend within the charted 5.4-meter contour as well (Figure 39).Comparison of surveyed soundings and US3GC06M charted depths in the northwestern portion of the survey area.SupportFiles\Fig38_H73-ChartComparison-US3GC06M-1.pngComparison of surveyed soundings and US3GC06M charted contour in the northeastern portion of the survey area.SupportFiles\Fig39_H73-ChartComparison-US3GC06M-2.pngNo Maritime Boundary Points were assigned for this survey.Prior to starting survey operations, the CSF indicates one pipeline, one cable, one weed/kelp area, 12 obstructions, three underwater/awash rocks and two wrecks within survey bounds. Seventeen ATONs and one Special/General Purpose buoy exist within survey bounds. Egmont Channel is located within survey bounds and the surrounding fairway and two anchorages are also partially present within the survey area. Nine dumping areas are partially present within survey bounds.An additional seventeen obstructions were added to the Final Feature File that were not addressed as DtoNs and not associated with charted (CSF) features. Refer to the Final Feature File for additional information. Contacts observed within the MBES data that were less than 1 meter in height were often 'Examined' to show they had been reviewed; these remain examined in the CARIS project. Twelve Dangers to Navigation were submitted for this survey. Refer to the Final Feature File for additional information.Egmont Channel is located within survey bounds. A comparison between the H13173_MB_50cm_MLLW_Final surface and Egmont Channel Dredged Area controlling depths was conducted. Chart US5FL11M was used to determine the controlling depths of the ROQ, RIQ, LIQ and LOQ. The ROQ (Right Outside Quarter) has a controlling depth of 12.80 meters. It was observed that nearly all surveyed depths from the H13173_MB_50cm_MLLW_Final surface were 12.80 meters or deeper with the exception of some small areas along the very outer edge of the ROQ. These areas appear to be less than 3 meters from the edge of the ROQ with depths only a few centimeters shallower than 12.8 meters. The RIQ (Right Inside Quarter) has a controlling depth of 13.60 meters. It was observed that nearly all surveyed depths from the 50 cm surface within the RIQ were 13.60 m or deeper with one area of exception (Figure 40). The LIQ (Left Inside Quarter) has a controlling depth of 13.50 meters. It was observed that nearly all surveyed depths from the 50 cm surface within the RIQ were 13.50 meters or deeper with one area of exception along the northern boundary (Figure 41). These depths are very close to 13.50 m and off by 1 or 2 cm. The LOQ (Left Outside Quarter) has a controlling depth of 10.10 meters. It was observed that nearly all surveyed depths from the H13173_MB_50cm_MLLW_Final surface were 10.10 meters or deeper with one exception along the northern boundary (Figure 42). Depths less than 10.10 meters extend less than 3 meters into the LOQ and drop off very quickly along this edge. Refer to Supplemental Survey Records and Correspondence for additional information.Comparison of surveyed depths to the controlling depth for Egmont Channel RIQ.SupportFiles\Fig40_H73-ChannelComparison-RIQ.pngComparison of surveyed depths to the controlling depth for Egmont Channel LIQ.SupportFiles\Fig41_H73-ChannelComparison-LIQ.pngComparison of surveyed depths to the controlling depth for Egmont Channel LOQ.SupportFiles\Fig42_H73-ChannelComparison-LOQ.pngEleven bottom samples were acquired within H13173 survey bounds in accordance with the locations in the PRF. Refer to the FFF for additional information.Shoreline was not assigned in the Hydrographic Survey Project Instructions or Statement of Work for this particular Sheet. However, 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 surveyed north of Egmont Channel. Please refer to the chart comparison section for additional information.No prior survey comparisons exist for this survey.Seventeen ATONs and one Special/General Purpose buoy exist within survey bounds. During field operations fixes were recorded in the acquisition logs, as well as heading and estimated distance to the buoys from the vessel (with the exception of Buoy 16 for which no estimated distance from the vessel was logged). Buoy positions were calculated from the aforementioned information and compared to both the CSF and Light List information. Egmont Channel Lighted Buoy 4 was noted as missing in the field project logs on 11/9/2019. Review of the District 7 Navigation Center Local Notice to Mariners indicates this buoy was noted as OFF STA/HAZ NAV/SINKING as of LNM 43/18 and discontinued as of LNM 44/18 dated October 31, 2018 with a note to temporarily Delete the buoy from charts 11412 and 11415. LNM 10/19 indicates this buoy was returned to the assigned position. The buoy was again noted as missing as of the 18/19 LNM and reset on location as of LNM 25/19. It is also recognized, as of LNM 43/18, that Egmont Channel Light Buoys 9, 11, 12, 13 were relocated for dredging operations. The proximity of the field fix positions to the relocated positions indicate the fixes were obtained at the temporary buoy positions. The other aids to navigation are determined to be on station. However, review of the Light List Volume III Atlantic and Gulf Coasts (2019) obtained here: https://www.navcen.uscg.gov/pdf/lightlists/LightList_V3_2019.pdf indicates several of the positions from the CSF are different than the positions listed. Please refer to Processed\Reports\Project\HVCR\Digital_B-Horizontal_Control_Data\ATON_Data for additional information.No overhead features exist for this survey.A portion of the 'Gulfstream Natural Gas System' pipeline, as labeled in the Composite Source File, extends east west through the central southwest portion of the survey area. Trench features are evident in the bathymetry data, as well as 2 potential pipeline exposures, which were submitted to BSEE as per the HSSD (2018). No large material coverings over the pipeline were observed. Data indicate the pipeline is well charted. One submarine cable is also present within the survey bounds. Bathymetric data do not indicate the presence of the cable. No platforms exist for this survey.No ferry routes or terminals exist for this survey.Drag scars are evident in the bathymetry data and two sets of three square features with numerous contacts were observed (Figure 43). These appear to be purposefully introduced and may be some sort of artificial fish haven, but the purpose is largely unknown.Abnormal seafloor feature evident in H13173 data.SupportFiles\Fig43_H73-AbnormalSeafloorFeature.pngReview of Local Notice to Mariners (LNM 39/18) indicate dredging activities in Egmont Key Channel (Cuts 1 and 2) in the eastern portion of the survey area commencing September 12, 2018 and ending approximately April 1, 2019. It is also recognized, as of LNM 43/18, that Egmont Channel Light Buoys 9, 11, 12, 13 were relocated for dredging operations. LNM review indicates at least Egmont Channel Lighted Buoys 11 and 12 were returned to their assigned positions as of LNM 06/19. According to LNM 20/19, dredging activities commenced in Egmont Channel Cuts 1 and 2 again around May 10, 2019 until approximately August 2019. However, the field survey logs and field correspondence do not indicate dredging or construction activities taking place during survey operations. No new surveys or further investigations are recommended for this area.No new insets are recommended for this area.As Chief of Party, field operations for this hydrographic survey were conducted under my direct supervision, with frequent personal checks of progress and adequacy.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.Scott MelanconChief of Party2019-08-16John BakerSenior Survey Technician2019-08-16Nicole GallowayGeoscientist2019-08-16Horizontal and Vertical Control Report2019-03-11Data Acquisition and Processing Report2019-06-28