S-B904-NRT5-14Narragansett Bay, RINarragansett Bay, RINavigation Response Team 5F006421Approaches to DavisvilleRhode IslandUnited States100002015LTjg Andrew R. ClosNavigable Area2014-06-272014-07-142015-05-15Multibeam Echo SounderSide Scan SonarmetersUniversal Transverse Mercator (UTM)UTCPacific Hydrographic BranchThe 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 considere 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/.NOAAThis survey was conducted in Narragansett Bay, in the vicinity north of Conanicut Island and towards Davisville Depot.41.619155555671.419638888941.560041666771.3467083333F00642 Survey Area.file:///M:/SB904NRT514/Surveys/F00642/Caris/Multimedia/SupportFiles/Area_Surveyed.bmpDue to safety concerns, there were a few small areas where the nearshore limit was not reached. See figure 2 below.Southwest portion of the sheet. Red areas indicate where the four meter contour was reached.file:///M:/SB904NRT514/Surveys/F00642/Caris/Multimedia/SupportFiles/4m_Curve.bmpThis survey was conducted at the request of the Northeast Marine Pilots Association to update survey data for the approaches to the piers at Davisville and Quonset, RI. Ship traffic to the facilities at Davisville is steadily increasing and the draft of the vessels calling on the port is getting deeper.The entire survey is adequate to supersede previous data.MBES coverage was acquired to pier faces at the Davisville Depot aside from a small section where construction was occurring. See figures 3 and 4 below. Depicting the extent of MBES coverage acquired near the piers at Davisville Depot, RI.file:///M:/SB904NRT514/Surveys/F00642/Caris/Multimedia/SupportFiles/F00642_PierCoverage.bmpShowing the NW portion of the wharf between pier 1 and pier 2 and floats marking an area where work was occurring. file:///M:/SB904NRT514/Surveys/F00642/Caris/Multimedia/SupportFiles/DavisvilleDepot_Pier%202.jpgSurvey coverage was in accordance with the requirements in the Project Instructions and the HSSD.Side scan coverage area for F00642.file:///M:/SB904NRT514/Surveys/F00642/Caris/Multimedia/SupportFiles/Coverage_SSS.bmpS3002026.84000185.6017.140026.84000185.6017.1408.16000002014-07-142014-07-152014-07-162014-07-172014-07-182014-07-212014-07-222015-05-132015-05-142015-05-15During the processing and data review, it was decided that more inshore coverage and additional development of areas of shoaling should be acquired. The team returned to the area for three days in May, 2015 to acquire this additional data. 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. MBES data acquired in 2015 utilized the 2014 DAPR and HVF values, therefore only the 2014 DAPR is submitted with this project. 2015 data was compared to 2014 over several features within the survey area and all data were found to be in agreement. Additionally, an abbreviated 2015 HSRR was carried out after this survey was completed and new HVF values were established. 2015 HVF values were in extremely close agreement with 2014, indicating negligible . Refer to the Project Correspondence folder for discussion regarding this matter. Refer to the "Additional Quality Control" section of this report for a discussion on the comparison of 2014 to 2015 data.S3002330.75S3002.file:///M:/SB904NRT514/Surveys/F00642/Caris/Multimedia/SupportFiles/nrt_underway.jpgS3002 acquired towed side scan data with concurrent multibeam, attitude data and bottom samples. KongsbergEM3002MBESEdgetech4125SSSApplanixPOS M/V V5Positioning and Attitude SystemTrimbleSPS361Positioning SystemSea-Bird ElectronicsSBE 19+Conductivity, Temperature, and Depth SensorAMLMicro XSound Speed SystemS3002 acquired 17.14 linear nautical miles of MBES cross lines, equating to 8.1% of mainscheme MBES data. Crosslines were compared to mainscheme using a difference surface, created in CARIS BathyDataBase. Using the difference surface, every instance of overlap was evaluated. The mean was 0.02 meters and the standard deviation was 0.05 meters. Survey F00642 complies with section 5.2.4.3 of the HSSD (2013 ed). Additional comparison was made using CARIS Subset Editor and a 50 centimeter BASE surface to visually identify areas of mainscheme/crossline disagreement. The highest areas of disagreement occurred near sand waves and the steep edges of the channel. S30022N/A.5F00642 utilized a TCARI grid, which includes uncertainty values for each node. Therefore, TPU values in CARIS were left at zero during TPU calculation. Total Propagated Uncertainty was then evaluated to ensure compliance with section 5.1.3 of NOAA's Hydrographic Survey Specification and Deliverables (HSSD). First, the maximum allowable uncertainty for each node was calculated. Second, the ratio between actual uncertainty and maximum allowed uncertainty was found for each node. The resulting 'Order_1a' layer was filtered using a color map to show any areas where actual uncertainty exceeded the maximum allowed uncertainty. Statistics were computed for the four meter BASE surface and of the 774,538 nodes, zero fell outside acceptable levels. Additionally, Order 1a statistics were computed for the 50cm BASE surface and of the 1,197,741 nodes, zero fell outside acceptable levels. No junctions were assigned for this survey.Sonar system quality control checks were conducted as detailed in the quality control section of the DAPR.None ExistThere were no conditions or deficiencies that affected equipment operational effectiveness.None ExistThere were no other factors that affected corrections to soundings.CTD casts were typically taken every two to three hours in the deepest area being surveyed at the time. The sound velocity profiles were applied to the MBES lines in Caris using the "nearest in time," method.Sound speed profiles in the area are most greatly affected by diurnal heating and cooling, and salinity fluctuations from the ebb and flood of the tide. "Nearest in time," provided the best results in this survey area. All equipment and survey methods were used as detailed in the DAPR.2014/2015 MBES ComparisonWhen the field unit returned to the survey are in 2015, a conspicuous feature was chosen as a reference object to compare MBES data between 2014 and 2015. The data was compared in CARIS Subset editor with point colors chosen based on day of collection. This visual comparison showed perfect agreement between the 2014 and 2015 MBES data. Overview of feature used for comparison. Red tracklines are from 2015, green tracklines are from 2014.file:///M:/SB904NRT514/Surveys/F00642/Caris/Multimedia/SupportFiles/2014-2015_Lines.bmpDark green soundings indicate MBES data from 2015, while bright green soundings were collected in 2014.file:///M:/SB904NRT514/Surveys/F00642/Caris/Multimedia/SupportFiles/2014-2015_Feature_Compare.bmpAll data reduction procedures conform to those detailed in the DAPR.All sounding systems were calibrated as detailed in the DAPR.Raw Backscatter was logged in the .all file. Backscatter was not processed by the field unit.CarisHIPS/SIPS81102015-01-16ProcessingNOAA Profile V_5_3_2All MBES and side scan data were converted and processed using a CARIS HIPS and SIPS 8.1.7. After acquisition was completed, data cleaning and additional processing was carried out on a different computer running CARIS HIPS and SIPS 8.1.10. No errors or anomalies were noticed when making this transition. The Hydro Systems Inventory contained in Appendix I of the DAPR notes the software versions used on each computer.F00642_MB_4m_MLLWCUBE41.8315.79NOAA_4mMBES TracklineSBES Set Line SpacingF00642_MB_4m_MLLW_FinalCUBE41.8315.79NOAA_4mMBES TracklineSBES Set Line SpacingF00642_MB_50cm_MLLWCUBE0.52.1510.59NOAA_0.5mMBES TracklineSBES Set Line SpacingF00642_MB_50cm_MLLW_FinalCUBE0.52.1510.59NOAA_0.5mMBES TracklineSBES Set Line SpacingF00642_1m_100SSS Mosaic11.8315.79N/A100% SSSF00642_1m_200SSS Mosaic11.8315.79N/A200% SSSFor the majority of the survey area, object detection requirements were achieved by acquiring "200% SSS with concurrent Set Line Spacing MBES." A 4m bathymetric grid was created for these areas. The southwest corner of the sheet is shallow and rocky. In that area, object detection requirements were achieved with Object Detection MBES. Throughout the survey, data density was high enough to support a 50cm grid, so a 50cm BASE surface has been submitted for the entire area. All designated soundings were picked from point cloud data, and each meets the requirements for designated soundings as specified in the HSSD. Per section 5.1.2.3 of the FPM, no Horizontal and Vertical Control Report has been generated for Survey F00642.Mean Lower Low WaterTCARIConimicut Light, RI845-2944Quonset Point, RI845-40498452944Final Approved8454094Final ApprovedB904NRT52014_Rev.tcFinal2014-08-132014-08-27CO-OPS accepted the preliminary TCARI grid as the final grid for survey F00642. Verified tides were downloaded and applied to the bathymetry using the Pydro Fetch Tides tool. Due to the survey being re-opened in May 2015, the request for final water levels was resubmitted in June 2015. Final water levels were received on July 8th, 2015.TCARI grid B904NRT52015.tc was applied to data acquired in 2015.North American Datum of 1983 (NAD83)UTM-19NSmart BaseURILURILACU5ACU5XMTSXMTSCTPUCTPUCTGRCTGRCTMACTMANPRINPRIMOR5MOR5Post Processed Kinematic GPS correctors were applied to all data except the following four lines: 0037_20140715_192653_S3002 0038_20140715_194937_S3002 0039_20140715_201306_S3002 0040_20140715_201732_S3002 These lines could not have IAPPK correctors applied, because they do not have Delayed Heave files associated with them. Using CARIS Subset Editor, these lines were compared to nearby lines that do have Delayed Heave and SBETs applied and the bathymetry was found to be in agreement. For more information regarding SBETs for this survey, refer to the SBET processing log.Moriches, NY (293kHz)F00642 was compared to affected RNC and ENC products by creating a high density sounding layer in CARIS BathyDataBase and comparing charted water depths with surveyed soundings.13223213420000432013-062014-06-282014-06-28Raster chart 13223 agreed very well with F00642. Surveyed soundings generally agreed with charted depths to within 2 feet. In the SW corner of the sheet charted 12 and 6 foot soundings were disproved by MBES. New contours should be drawn in these areas. See figure below.Southwest corner of sheet highlighting chart comparison.file:///M:/SB904NRT514/Surveys/F00642/Caris/Multimedia/SupportFiles/ShoalSoundingsSW.bmpUS5RI22M20000232015-01-27falseElectronic chart US5RI22M agreed very well with F00642. Surveyed soundings generally agreed with charted depths to within 2 feet.16 assigned features were investigated by this survey. For more information, refer to the final feature file: F00642_FFF.hob.There were no assigned AWOIS items for this survey.No Maritime Boundary Points were assigned for this survey.No charted features exist for this survey.There were 42 assigned features, 18 of which were investigated in this survey. In addition to the 16 assigned features that were investigated, 2 more features were discovered and are included in the Final Feature File.No Danger to Navigation Reports were submitted for this survey.In the southwestern portion of the sheet, a charted 12 foot sounding exists and evidence of a shoal was found with MBES and 200% SSS data. The least depth found by MBES was 12.4 feet. No charting changes are recommended. 12 foot shoal, MBES coverage.file:///M:/SB904NRT514/Surveys/F00642/Caris/Multimedia/SupportFiles/12footshoal.jpg12 foot shoal SSS coverage, showing shadow height of feature.file:///M:/SB904NRT514/Surveys/F00642/Caris/Multimedia/SupportFiles/12footshoal_SSS.jpgSurvey F00642 was conducted at the request of the Northeast Marine Pilots Association to investigate the channel that runs along the north and east sides of Conanicut Island, then along Quonset Point to the Davisville Depot piers. This channel is frequently traveled by roll on, roll off car carriers with drafts up to 30 feet. Special attention was given to the chart comparison within the channel. In all areas of the channel, surveyed soundings were equal to or slightly (1 to 2 feet) deeper than charted. In total, 6 bottom samples were collected and these results were compared to charted bottom types. See the final feature HOB file for more details.Limited shoreline verification was performed and all features included in the CSF and falling within the survey limits were verified. Some features were inshore of the 12 foot contour (near shore limit) and could not be verified. No prior survey comparisons exist for this survey.All ATONs were observed to be on station and in satisfactory condition during the acquisition phase of F00642. Observations were only made during day time, so no assessment of light functionality was made. No changes are necessary to charted ATONs.No overhead features exist for this survey.Multiple cable areas exist throughout the survey area, but very little evidence of their presence was found in the MBES data. No ferry routes or terminals exist for this survey.An internal discrepancy report no. 28828 was submitted to NOAA's marine chart division on 10/12/16 reporting the uncharted ferry route.A platform exists in the southwestern portion of the sheet. Just south of Quonset Point, is a jetty that extends about 330 meters feet seaward. 50 meters seaward of the end of the jetty is a small platform. MBES data was acquired around this platform and it appears to be well charted. MBES coverage around charted platform.file:///M:/SB904NRT514/Surveys/F00642/Caris/Multimedia/SupportFiles/Platform_Quonset_point.jpgPicture of platform extending from shore.file:///M:/SB904NRT514/Surveys/F00642/Caris/Multimedia/SupportFiles/IMG_20150515_122352821.jpgNo significant features exist for this survey.The main channel and areas surrounding pier 1 and pier 2 at the Davisville Depot are regularly dredged. Soundings from this survey, in these controlled areas, were found to be equal to or slightly (1-2 feet) deeper than charted. No new surveys or further investigations are recommended for this area.No new insets are recommended for this area.As Chief of Party, field operations for this hydrographic survey were conducted under my direct supervision, with frequent personal checks of progress and adequacy. I have reviewed the attached survey data and reports.All field sheets, this Descriptive Report, and all accompanying records and data are approved. All records are forwarded for final review and processing to the Processing Branch.The survey data meets or exceeds requirements as set forth in the NOS Hydrographic Surveys and Specifications Deliverables Manual, Field Procedures Manual, Letter Instructions, and all HSD Technical Directives. These data are adequate to supersede charted data in their common areas. This survey is complete and no additional work is required with the exception of deficiencies noted in the Descriptive Report.Andrew R. ClosSheet Manager2016-02-15