Deals with the measurement and description of the features of the seas and coastal areas for the primary purpose of navigation

Hydrography

GPS Satellites

Kinematic GPS

Plate Boundary

Reference PointsOn land

Acoustic Ranging

Seafloor Reference Point

Trench

Survey Vessel

Slide credit: Masayuki FUJITA, Japan Coast Guard

Hydrographers use many high tech tools

Receive Beams20 - 1440 “beams”20° fore-aft, 1° - 5° athwart

Transmit Beam1° - 5° fore-aft90° - 170° athwart

Depth PointIntersection of the transmit beam and one of the receive beams

Slide credit: Dave Wells

Multibeam Sonar

Rendered by Sirius Solutions, Dartmouth NSRendered by Sirius Solutions, Dartmouth NS

Slide credit: Dave Wells

Pockmark found in English Bay

To obtain dramatic results such as a view of the Empress of Ireland