It is brightly colored protective capsule and may be fitted with an appropriate device to aid location . It may be in a retrievable fixed unit or free float unit (or combined with EPIRB) when the ship sinks in marine incident, the last 12 hours of stored data in the protected unit can be recovered and replayed by the authorities or ship owners for incident investigation.
The Voyage Data Capsule continuously records 12 hours of data from the VDR system. The VDC completely fulfils the requirements in the test standard IEC 61996.
Capsule must be provided with radar reflectors and special color and special frequency above the water and sound frequency under the water.