AV Training Presentation Seven Taking and Reporting Depths to a Government Agency.

Elements of a Depth Report 1. Charted depth – Taken from the NOAA Chart. 2. Correction for the location of the echo sounder’s transducer. 3. Reading from the vessel’s echo sounder. 4. HOT – Height of Tide at the time that the depth was read.

Initial set up requirements 1. List the manufacturer’s name and model number of the echo sounder on your NS-PN04 Private Aid to Navigation Report. 2. Measure the distance from the location of the transducer to the waterline on your OPFAC. Or, add this information to your “Accuracy Statement” for use on the Web-Based PATON System.

Sample “Accuracy Statement” GPS 76 by GARMIN with WAAS enabled in 3D Differential was used for fix. GPS was pre-checked at the dock with another GPS set. On-scene EPE was 6.7 feet. Wide 100 echo sounder by Hummingbird that was pre- checked at the dock with a lead line. Substation used was Neponset River. Correction for transducer was 0.9 ft. White = Data normally stays the same while you are on your own OPFAC. Yellow = As you move around, this data will change for each verification.

Perform a pre-underway check of the echo sounder. 1.Confirm that the vertical datum on the echo sounder matches the vertical datum on the NOAA chart being used. Confirm that the echo sounder is operating accurately bu using a: a. Lead line. b. Sounding pole, or by c. Calculation. 3.Establish the correct “Substation” on the “Tide and Current” screen on your GPS. 3. Update your “Accuracy Statement”

Taking the sounding for the PATON 1. Take the sounding while close aboard the PATON while in the channel. 2. Record the depth reading from the echo sounder. 3. Record the date and time when the depth was taken. 4. Record the HOT - Height of Tide from the Almanac screen on your GPS. 5. Re-check that the “Substation” is correct. 6. Record the charted depth for the PATON.

Correcting the depth to charted datum Echo sounder readout : 9.5 feet PLUS Correction for transducer: 0.9 feet MINUS HOT- Height of Tide: 2.3 feet EQUALS Estimated Depth at Datum 8.1 feet Compare Estimated Depth at Datum to Charted Depth. Make a statement in the Comments Section, if needed.

AV Task Enter the depth data on the your NS-PN04 Private Aid to Navigation Report. Sounding feet. Transducer correction – 0.9 feet. Height of tide feet. Charted depth – 8.0 feet. Calculate Estimated Depth at Datum. Calculate Depth Difference (Estimated Depth at Datum versus Charted Depth.)

Update the observed sounding data to the “NS-PN04 Private Aid to Navigation Report.” Accuracy Statement Update for the “Web-based PATON System” Wide 100 echo sounder by Hummingbird was pre-checked at the dock with a lead line. Substation used is Neponset River. Correction for transducer is 0.9 ft.