VDR (Voyage Data Recorder)
The ship's 'black box': what it actually records, when it must be checked, and why its proper maintenance is often neglected until it is needed — too late.
Operational Explanation
The Voyage Data Recorder (VDR) continuously records critical navigational data (position, heading, speed, bridge radio and VHF communications, radar images, AIS data, alarms, and helm and engine commands) for a minimum period, enabling reconstruction of events in the event of an incident.
A VDR that is installed but not functioning correctly, or whose data cannot be retrieved when needed, defeats the entire purpose of the equipment: maintenance and periodic verification (including the annual performance test) are just as important as the initial installation.
2026 update — electronic inclinometers connected to the VDR: Resolution MSC.532(107) introduces the new paragraph SOLAS Regulation V/19.2.12, which requires the installation of an electronic inclinometer on board new container ships and bulk carriers of 3,000 gross tonnage and above with keel laid on or after 1° January 2026. The instrument, type-approved to the performance standards of Resolution MSC.363(92), must determine, display and record the ship's rolling motion, supplying the VDR with additional data useful both for real-time decision-making on trim and operational stability, and for post-incident reconstruction in casualties involving cargo shift, container loss or dynamic separation of bulk cargo. The new requirement does not apply to existing ships, nor to cargo ships that carry bulk cargo only occasionally, nor to general cargo ships carrying containers on deck only.
Regulatory Reference
SOLAS Chapter V, Regulation 20 (Voyage Data Recorders): installation required for passenger ships and cargo ships according to applicable tonnage thresholds; performance standards under Resolution MSC.333(90), as amended by MSC.494(104), for VDRs installed on or after 1° July 2022. Annual performance test required by an authorised organisation. SOLAS Regulation V/19.2.12 (Res. MSC.532(107)), in force from 1° January 2026: electronic inclinometer connected to the VDR required for new container ships and bulk carriers ≥3,000 GT with keel laid on or after that date, type-approved to Res. MSC.363(92).
Scope of Application
Passenger ships regardless of build date, and cargo ships of gross tonnage at or above the applicable thresholds, according to the SOLAS V/20 phase-in schedule.
Procedure / How to Complete It
- Verify that the VDR is operating continuously during navigation, recording all required channels (position, communications, radar images, AIS data).
- Carry out the annual performance test through an authorised organisation, verifying the integrity and readability of the recorded data.
- Periodically check the protective capsule (fixed or float-free) and the underwater locating device associated with the VDR.
- In the event of an incident or significant near-miss, immediately safeguard the VDR data for the relevant period, before it is overwritten by the continuous recording cycle.
- Keep documentation of the last annual performance test on board, available for PSC verification.
- For new container ships and bulk carriers ≥3,000 GT with keel laid on or after 1° January 2026, verify installation and correct operation of the electronic inclinometer connected to the VDR, type-approved to Resolution MSC.363(92).
Practical Example
Example post-incident procedure: following a near-grounding, the officer of the watch immediately requests that the VDR data for the preceding 12 hours be saved to external media, before the recorder's overwrite cycle can delete information relevant to the subsequent analysis.
Real Cases
Common Mistakes Mistake Library
| Mistake | Consequence | How to avoid it |
|---|---|---|
| Annual performance test not carried out or overdue | PSC deficiency, risk that the VDR will not function correctly when needed | Schedule the annual performance test together with the other statutory surveys, without delay |
| VDR data not promptly safeguarded after an incident or near-miss | Permanent loss of information critical to the investigation, through overwriting by the continuous recording cycle | Train the crew to immediately safeguard the relevant data after every significant event |
| Protective capsule or underwater locating device not periodically checked | Inability to recover data in the event of loss of the ship | Include verification of the capsule and locating device in the periodic maintenance programme |
PSC Observations
Operational Tips
- Do not treat the annual performance test as a minor formality: always verify its actual outcome, not just its formal completion.
- Train the crew to immediately safeguard VDR data after every significant event, without waiting for instructions from the Company.
- Include the protective capsule and underwater locating device in the periodic maintenance programme, not just the recorder itself.
Checklist
- VDR operating continuously with all required channels active
- Annual performance test carried out and documented
- Protective capsule and underwater locating device periodically checked
- Post-incident data safeguarding procedure known to the crew
- Documentation of the last test available on board for PSC verification
- For new ships subject to the requirement (container ships/bulk carriers ≥3,000 GT, keel laid from 2026): electronic inclinometer installed, functioning and connected to the VDR