The IMO defines the Voyage Data Recorder as a complete system, including any items required to interface with the sources of input signals, their processing and encoding, the final recording medium, the playback equipment, the power supply and dedicated reserve power source.

Akin to the ‘Black Box’ on airplanes, a Voyage Data Recorder is an equipment fitted onboard ships that record the various data on a ship which can be used for reconstruction of the voyage details and vital information during an accident investigation.

Information is stored in a secure and retrievable form, relating to the position, movement, physical status, command and control of a ship over the period and following an incident. This information is used during any subsequent safety investigation to identify the cause(s) of the incident. Aside from its usage in accident investigation, it can also be used for preventive maintenance, performance efficiency monitoring, heavy weather damage analysis, accident avoidance and training purposes to improve safety and reduce running costs.