NOAA Charting - Alabama, Louisiana and Mississippi Gulf of Mexico

We conducted two hydrographic surveys after hurricanes hit western Florida, Alabama, Mississippi, and Louisiana. The survey areas encompassed approximately 112 square nautical miles of sea floor.

This project required the installation of two water level tide stations to establish tidal datum. One station was located in Perdido Bay, and the other at Alabama Point.

We provided 100% sidescan coverage in areas as shallow as four feet. The shallower water areas were surveyed with the M/V Royal Fish, a 25' jet boat using a Benthos C3D interferometric sidescan and a vertical beam echosounder. Our boat surveyed as a "day" boat from shore and worked with a Reson 8124 and an EdgeTech DF1000 in areas as shallow as four meters. The shallow areas were surveyed to the same specifications as the deeper areas.

The M/V Bella Marie, our 39' catamaran surveyed the deeper parts of Perdido Bay and the area outside the bay with a Reson 8124 multibeam and an EdgeTech 4200S high speed sidescan.

For these surveys we:

• Acquired shallow water multibeam sounding data;


• Acquired sidescan sonar data;


• Determined positions and least depths on hazards to navigation;


• Installed and operated 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, and DGPS checks;


• 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 and digital data; and


• Performed quality control during data acquisition and processing.

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