
BATHIMETRY SURVEY
This Bathymetry Survey Service is in principle similar to topographical mapping and measurement, but this survey is used for marine surveys (ocean / ocean depth mapping). Include a survey for the tides. Originally, bathymetry involved measuring the depth of the ocean by means of sounding depths.
Early techniques used pre-set heavy ropes or cables lowered over the side of the boat. This technique measures the depth of only a single point at a time, and is therefore inefficient. It is also subject to ship movements and currents which move out of alignment and is therefore inaccurate.