NOAA Charting - Port Clarence and Nome Norton Sound, Alaska

The hydrographic surveys were conducted to provide NOAA with modern, accurate hydrographic survey data to update the nautical charts of the area. These charts are important for the people in the area who rely heavily on the marine environment for mining, fishing, shipping, and transportation.

The surveys were accomplished with the M/V Bristol Endeavor, a 71.5' steel hull boat and the M/V Peregrine, a 90' aluminum hull, landing craft boat, both vessels of opportunity. The Bristol Endeavor was equipped with a Reson 8101 multibeam system that was used to locate and determine the least depth over the obstructions, wrecks and shoals as well as to determine the least depths over the project area. The Peregrine was equipped with a pole-mounted Odom Echotrac single beam echosounder and an EdgeTech 4200-FS side scan sonar towfish.

Other systems used during the surveys were a Reson SeaBat 81-P sonar processor, Seatex Seapath 200 RTK positioning system, Seatex MRU-5 motion sensor, and Applied Microsystems SV Plus (500 dBar) sound velocity meter.

For these tasks we:

• Collected shallow water multibeam sounding data;
• Collected side scan sonar data;
• Determined positions and least depths on hazards to navigation;
• Installed, operated and removed water level (tide) stations;
• Acquired related supporting data including, water level correctors, velocity of sound in the water column, vessel motion correctors, bottom sediment samples, shoreline verification, DGPS checks and more;
• Processed the data including tidal tabulation, computation of tidal datums, tidal zoning determination, applying water levels, vessel motion and velocity of sound correctors to determine the true depths, correlating sonar targets, and compiling reports, final smooth sheets, and digital data;
• Performed quality control during data acquisition and processing;
• Delivered raw and processed data, reports and sheets for archiving and use in updating nautical charts; and
• Performed to NOAA specifications and provided the deliverables in NOAA specified formats.

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