Dredging

Charting & Maintenance Dredging

Precise and accurate mapping of the coastal zone especially around port approaches and in shipping lanes is essential for charts to show maritime users the seabed morphology and submarine features. Safety and efficiency require route entrances and berths to be clear of obstacles and of adequate depth as shown on the charts.

Coastline Surveys Limited undertakes regular bathymetric surveys of ports, harbours and marinas and their approaches. These are carried out using the most time & cost effective method of positioning to give the desired coverage and accuracy. These include not only DGPS, but also RTK-GPS in the horizontal plane and digital echosounder data with heave compensation in the vertical plane. Track charts, soundings and bathymetry plots to the Client’s required scale and datum are produced with the report and 3D digital terrain modelling is available.

Areas of hazards may be identified more efficiently by sidescan sonar imaging over an area greater than is practicable by echosounding techniques, especially in shallower water.

To supplement the bathymetry data and aid interpretation for a comprehensive study of a port/marina or its approaches, current measurements (direction and magnitude) may be monitored, samples of the bottom sediment removed by grab, and water sampling and environmental monitoring undertaken to ensure detection of any pollution disturbance caused by activities such as dredging.