Data were collected from 11 September 2014 to 21 September 2016.

Sidescan sonar imagery (GeoTIFF) is available for qualitative purposes. The sidescan range violated the 1:10 depth: range ratio rule-of-thumb, as range was to 50x water depth.

Bathymetric point data from Singlebeam Echosounder (ArcGIS Shapefile and CSV).

Bottom features including Maximum SV, First echo, second echo, kurtosis, skew, rise, hardness, and roughness (see EchoView support for description of these features)

• Caution should be used when interpreting all bottom features other than depth(bathymetric data are acceptable). Poor weather and resulting heave affected the signal for some survey days. In general, the singlebeam data in the southwest portion of the bay is reliable. The use of the features to automate a habitat classification is not suggested.

• Sidescan = Teledyne Benthos C3D

  • Bow-mounted

  • 200 kHz frequency

  • Range of 100 meters

  • 12% Overlap between transect

  • Transect spacing of 185 meters

  • Data collected in WGS 84

  • Projected to UTM 15N

  • Location Data: Ashtec dGPS receiver with Communication System International MBX-3 Differential

• Singlebeam

  • Processed in EchoView

  • Bottom Line Selection

    • Min SV for pick = -9

    • Backstep @ -15 discrimination level

    • Peak threshold = -13

  • Bottom Classification (to pull features)

    • Distance between intervals = 5 m

    • Background noise = -999

    • Bottom echo threshold @ 1 m = ranges from -60 to -40

  • Final SingleBeam file

    • “Dep_Orig” = raw depth values that were all calculated using a 0.495 m transducer offset, have not been corrected for transducer offset error in 2014/2015. If you want to use these, then:

      • Data from 2016 is correct

      • Data from 2014-2015 needs to have 0.15 m ADDED to it

    • “Depth” = depths that have been corrected for transducer offset

    • “Dep_TidCor” = Transducer-corrected depths that have been corrected for tide

      • Tide corrections in 1-hour intervals from Pier 21

    • All depths are in meters

• Survey planning in Hypack

Disclaimer: This product is for informational purposes only and may not be suitable for legal, engineering, or surveying purposes. It does not represent an official survey and represents only the approximate relative location of features and boundaries. Mapping may not necessarily reflect on-the-ground conditions. This product and those involved in its production make no claims as to the accuracy or reliability of the data, and neither assumes, nor will accept liability for their use.

Data were collected from 11 September 2014 to 21 September 2016.

Sidescan sonar imagery (GeoTIFF) is available for qualitative purposes. The sidescan range violated the 1:10 depth: range ratio rule-of-thumb, as range was to 50x water depth.

Bathymetric point data from Singlebeam Echosounder (ArcGIS Shapefile and CSV).

Bottom features including Maximum SV, First echo, second echo, kurtosis, skew, rise, hardness, and roughness (see EchoView support for description of these features)

• Caution should be used when interpreting all bottom features other than depth(bathymetric data are acceptable). Poor weather and resulting heave affected the signal for some survey days. In general, the singlebeam data in the southwest portion of the bay is reliable. The use of the features to automate a habitat classification is not suggested.

• Sidescan = Teledyne Benthos C3D

  • Bow-mounted

  • 200 kHz frequency

  • Range of 100 meters

  • 12% Overlap between transect

  • Transect spacing of 185 meters

  • Data collected in WGS 84

  • Projected to UTM 15N

  • Location Data: Ashtec dGPS receiver with Communication System International MBX-3 Differential

• Singlebeam

  • Processed in EchoView

  • Bottom Line Selection

    • Min SV for pick = -9

    • Backstep @ -15 discrimination level

    • Peak threshold = -13

  • Bottom Classification (to pull features)

    • Distance between intervals = 5 m

    • Background noise = -999

    • Bottom echo threshold @ 1 m = ranges from -60 to -40

  • Final SingleBeam file

    • “Dep_Orig” = raw depth values that were all calculated using a 0.495 m transducer offset, have not been corrected for transducer offset error in 2014/2015. If you want to use these, then:

      • Data from 2016 is correct

      • Data from 2014-2015 needs to have 0.15 m ADDED to it

    • “Depth” = depths that have been corrected for transducer offset

    • “Dep_TidCor” = Transducer-corrected depths that have been corrected for tide

      • Tide corrections in 1-hour intervals from Pier 21

    • All depths are in meters

• Survey planning in Hypack

Disclaimer: This product is for informational purposes only and may not be suitable for legal, engineering, or surveying purposes. It does not represent an official survey and represents only the approximate relative location of features and boundaries. Mapping may not necessarily reflect on-the-ground conditions. This product and those involved in its production make no claims as to the accuracy or reliability of the data, and neither assumes, nor will accept liability for their use.