S-B904-NRT5-14Narragansett Bay, RINarragansett Bay, RINavigation Response Team 5F006432Conimicut Point ReachRhode IslandUnited States100002014LTjg Andrew R. ClosNavigable Area2014-06-272014-07-212014-07-23Multibeam 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 considered preliminary unless otherwise noted. The final disposition of surveyed features is represented in the OCS nautical chart update products. All pertinent records for this survey, including the DR, are archived at the National Centers for Environmental Information (NCEI) and can be retrieved via http://www.ncei.noaa.gov/.NOAAThis survey was conducted in Narragansett Bay, in the vicinity of Conimicut Point Reach.41.731344444471.371736111141.714622222271.3378722222F00643 Survey Area.file:///M:/SB904NRT514/Surveys/F00643/Caris/Multimedia/F00643_Area_Surveyed.bmpThe four meter curve was reached for the entire survey, except for a small portion just southeast of Conimicut Light. Due to the proximity of the rip rap around the light, the jetty to the south of the survey area, and shallow water to the west, the vessel could not be safely maneuvered to reach the four meter curve. See figure 2 below.Red areas indicate where the four meter contour was reached.file:///M:/SB904NRT514/Surveys/F00643/Caris/Multimedia/F00643_4m_Curve.bmpThe purpose of this project is to provide contemporary surveys to update National Ocean Service (NOS) nautical charting products. This survey was conducted at the request of the Northeast Marine Pilots Association to investigate the possibly of deeper water being found to the south of the maintained channel. If deeper water is present south of the channel, the pilots will request that AtoNs be moved and the channel widened to provide a better location for large vessels to safely meet or pass each other. The entire survey is adequate to supersede previous data.During acquisition of main scheme data on F00643, a feature was noticed just southeast of the survey area and close to the maintained channel. After analysis, the feature was determined to be real, but its least depth falls within the range of the surrounding depths and poses no hazard to navigation. For more information, please refer to the Final Feature .hob file.Additional MBES data acquired outside of the assigned survey area.file:///M:/SB904NRT514/Surveys/F00643/Caris/Multimedia/Feature_Outside_Survey_Area.bmpThe Final Feature file is not appended to this report.Side scan coverage area for F00643.file:///M:/SB904NRT514/Surveys/F00643/Caris/Multimedia/F00643_Coverage_SSS.bmpS3002013.3400015.8803.780013.3400015.8803.78012.92100002014-07-212014-07-222014-07-23Refer 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.S3002330.75S3002file:///M:/SB904NRT514/Surveys/F00643/Caris/Multimedia/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 3.78 linear nautical miles of MBES cross lines, equating to 12.9% 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 0.04 meters and the standard deviation was 0.02 meters. Survey F00643 complies with section 5.2.4.3 of the HSSD (2013 ed). S30022N/A.5F00643 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 50cm BASE surface and of the 5,828,916 nodes, zero fell outside acceptable levels. During office review the following stats were calculated for the 50cm Final BASE surface: 99.9 % nodes pass (5,828,491 out of 5,828,508 nodes)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.All 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.F00643_MB_50cm_MLLWCUBE0.5020.12NOAA_0.5mObject DetectionF00643_MB_50cm_MLLW_FinalCUBE0.52.7920.14NOAA_0.5mObject DetectionF00643_1m_100SSS Mosaic1022N/A100% SSSF00643_1m_200SSS Mosaic1022N/A200% SSSF00643_MB_4m_MLLWCUBE4020.05NOAA_4mMBES TracklineSBES Set Line SpacingF00643_MB_4m_MLLW_FinalCUBE42.8320.05NOAA_4mMBES TracklineSBES Set Line SpacingIn the shallow portions of the sheet, outside of the channel, survey coverage requirements were fulfilled by acquiring "200% SSS with concurrent Set Line Spacing MBES." Within the channel and at the extreme nearshore area in the southwest, object detection MBES coverage was acquired. Therefore, both a 4 meter CUBE surface, and a 50 centimeter CUBE surface are included. Density statistics were calculated for the 50cm BASE surface. 97.42% of all nodes contained 5 or more soundings. Areas with the lowest sounding density occurred inside the channel at water depths greater than 16 meters where ping rate was slowest.Per section 5.1.2.3 of the FPM, no Horizontal and Vertical Control Report has been generated for Survey F00643.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 F00643. Verified tides were downloaded and applied to the bathymetry using the Pydro Fetch Tides tool.See attached Tide Note dated August 14, 2014.North American Datum of 1983 (NAD83)UTM-19NSmart BaseURILURILACU5ACU5XMTSXMTSCTPUCTPUCTGRCTGRCTMACTMANPRINPRIMOR5MOR5For more information regarding SBETs for this survey, refer to the SBET processing log.Moriches, NY (293kHz)F00643 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.13224213220000402013-042015-03-212015-03-21Raster chart 13224 agreed very well with F00643. Surveyed soundings generally agreed with charted depths to within 1 foot.US5RI23M20000232015-01-12falseElectronic chart US5RI23M agreed very well with F00643. Surveyed soundings generally agreed with charted depths to within 1 foot.One assigned feature was investigated by F00643 and found to be charted accurately. For more information, refer to the final feature file: F00643_FFF.hob.The AWOIS item was #14540. See attached Feature Report. F00643_FFF.hob is not appended to this report.No Maritime Boundary Points were assigned for this survey.No charted features exist for this survey.Just outside of the assigned survey area, to the southeast, a potential feature was noticed in MBES data during acquisition. This area was thoroughly investigated with multibeam and a the feature was developed. For more information, refer to the final feature file: F00643_FFF.hob.F00643_FFF.hob is not appended to this report.No Danger to Navigation Reports were submitted for this survey.No shoals or potentially hazardous features exist for this survey.Survey F00643 was conducted at the request of the Northeast Marine Pilots Association to investigate Conimicut Point Reach and determine if sufficient water depths exist outside of the channel to justify widening the channel at this location. F00643 confirmed control depths within the channel and found that soundings outside of the channel appear to be accurately depicted on the chart. In total, 2 bottom samples were collected and these results were compared to charted bottom types. For more details, see the final feature file: F00643_FFF.hob.F00643_FFF.hob is not appended to this report.Limited shoreline verification was performed and all features included in the CSF and falling within the survey limits were verified. One feature was 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 serving their intended purpose during the acquisition phase of F00643. 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.No submarine features exist for this survey.There is a cable area that is partially within the limits of this survey. There is no evidence of cables in the area covered by the survey.No ferry routes or terminals exist for this survey.No platforms exist for this survey.No significant features exist for this survey.The channel is dredged regularly and in all areas surveyed depths are equal to or deeper than tabulated depths on raster chart 13224.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 Manager2016-02-19