Data Retention of VDR

One of the most significant changes in the revised performance standards from a data analysis perspective is the requirement that VDRs must now be capable of storing data for a longer duration — at least 30 days / 720 hours.

The performance standard also mandates that the system must include a data output interface using an internationally recognized format (e.g., Ethernet, Universal Serial Bus (USB), Firewire, etc.), allowing users to download data over a user-defined period.

The original IMO resolution on VDR performance standards only required a minimum data retention of 12 hours. As a result, such data were often overwritten before being downloaded or preserved. The extended recording requirement significantly improves the likelihood that data will be available and retrievable after many types of incidents, even without someone needing to manually save it within 30 days after the event. It also provides greater scope for analyzing long-term trends and assessing navigational behavior on the bridge team, along with evaluating a vessel's Safety Management System (SMS) navigation policies — as part of a proactive approach.

In addition to the requirement for extended-duration recording, the revised regulation also mandates that the VDR be equipped with a fixed, non-float-free recording medium (capsule), capable of retaining the most recent 48 hours of data. Previous IMO performance specifications only required either a fixed or float-free recording medium that stored the past 12 hours of data. This change enhances the likelihood of data recovery in the event of major accidents, such as vessel sinking or fire.