In order to keep IIM publications and charts constantly updated, in particular as regards depths, seafloor, coastlines, harbours and ports, lights and fog signals, IIM regularly plans and carries out hydrographic and geodetic surveys, using their own specialized military and civilian staff and survey boats, as well as Italian Navy units. 

IIM survey boats are fully equipped with positioning systems and multibeam echo sounders.

Geodetic surveys include a number of different operations – starting from fundamental geodetic points to coastal relief and hydrographic surveys.





Through hydrographic surveys the seabed is mapped out and depth measured throughout against a reference level called “Mean Lower Low Water”.
Data collected during geodetic and hydrographic surveys are processed, validated and logged into IIM databases, to be used for the compilation of nautical publications.