Assembled from thousands of commercial fishing vessels, the Olex global bathymetric
database has more than two billion soundings covering an extensive area. All the
data are contributed voluntarily and in return for sharing their own data an Olex
user will gain access to the shared database. In operation now for more than a decade
this cooperative approach has produced one of the largest collections of marine data
in the world.
In addition to its broad spatial coverage the Olex data set is of a very high resolution
(5 metres), whereas other global bathymetry datasets are typically at a resolution
of hundreds or thousands of metres.
The data are collected using standard commercial single-beam echosounders and GPSs.
The data produce very good results when compared to hydrographic-standard multibeam.
The data are corrected with predicted tides and use local chart datum as their reference
level.