Operational guide · Safety & equipment

VDR (Voyage Data Recorder)

Q: How often must the VDR annual performance test be carried out?

Annually. SOLAS V/18.8 assigns it to an “approved testing or servicing facility” and gives it a precise object: to verify “the accuracy, duration and recoverability of the recorded data”. A copy of the certificate of compliance stays on board, and it is the document from which the applicable standard can be read.

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.

VDRS-VDRSOLAS Chapter Vdata recording

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.

How many hours, in fact: it depends on when the VDR was installed

“A minimum period” is not an operational figure. The figures exist, and there are two different sets, because the criterion is not the age of the ship but the date the equipment was installed. Res. MSC.333(90) says so itself, recommending that Governments ensure VDRs “if installed on or after 1 July 2014, conform to performance standards not inferior to those specified in the annex to the present resolution” and, if installed earlier, to the preceding standard. There is no mandatory retrofit: in 2026 there are still ships whose VDR lawfully retains twelve hours.

Equipment	Standard	Minimum duration
VDR: before 1 July 2014	A.861(20); MSC.214(81) from 1 June 2008	12 h
VDR: from 1 July 2014	MSC.333(90), §5.4.3	48 h on fixed and float-free media; 720 h on long-term medium
VDR: from 1 July 2022	MSC.333(90) + MSC.494(104)	Same windows; six months after recording ends already required for float-free
S-VDR	MSC.163(78), §5.3.3	12 h

Recording windows are minimum durations, not deadlines allowing preservation to be delayed. Six-month retention after recording ends in the float-free capsule was already required by MSC.333(90), §5.2.2.2; MSC.494(104) retains it and updates capsule and signalling requirements.

After an incident: who saves the data, and with how much margin

SOLAS sets no hourly deadline for saving the data. There is a guideline, MSC/Circ.1024, and a qualitative criterion: “Recovery of the VDR information should be undertaken as soon as possible after an accident to best preserve the relevant evidence”. Responsibility rests with the owner, “through its on-board standing orders”; the Master acts “where time and other responsibilities permit”. So the real deadline is not set by the rule: it is set by the overwrite cycle of the equipment actually installed, which is one more reason to know which of the two standards applies to your ship.

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 — roll motion: SOLAS V/19.2.12 requires containerships and bulk carriers of at least 3,000 GT constructed on or after 1 January 2026 to carry an electronic inclinometer, or other means, to determine, display and record roll motion. Where an electronic inclinometer is used, MSC.363(92) provides its performance standards and standardized interface to the VDR.

Regulatory Reference

SOLAS Chapter V, Regulation 20 (Voyage Data Recorders): installation required for passenger ships and cargo ships according to applicable tonnage thresholds — the S-VDR is admissible only for cargo ships constructed before 1 July 2002. Retention: Res. A.861(20), §5.3.3, twelve hours for VDRs installed before 1 July 2014; Res. MSC.333(90), §5.4.3, 48 hours on the fixed and float-free capsules and 30 days on the long-term recording medium for those installed later. SOLAS V/18.8 for the annual check: the system “shall be subjected to an annual performance test” conducted by an “approved testing or servicing facility” to verify “the accuracy, duration and recoverability of the recorded data”, with a copy of the certificate of compliance retained on board; procedure in MSC.1/Circ.1222/Rev.1. Recovery of data after an incident: MSC/Circ.1024. 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 organization. SOLAS Regulation V/19.2.12 (Res. MSC.532(107)), in force from 1 January 2026: electronic inclinometer, or other means, for containerships and bulk carriers ≥3,000 GT constructed on or after that date; inclinometer performance under Res. MSC.363(92).

VDR and S-VDR have different standards and channels: check approved type, installation date, manual and annual-test report. Do not automatically apply the full-VDR installation timeline to S-VDRs. IMO: VDR / S-VDR.

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 organization, 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 containerships and bulk carriers ≥3,000 GT constructed on or after 1 January 2026, verify an electronic inclinometer or other means compliant with SOLAS V/19.2.12; if an inclinometer is fitted, verify MSC.363(92) and the VDR interface.

Practical Example

After a near-grounding, as soon as ship safety permits, activate the preservation function specified by the manual and SMS. Verify that the relevant period is protected and retrievable; document preservation and arrange data recovery. Do not wait for the minimum window to expire or assume every channel is available on every recorder.

What Typically Goes Wrong

In several maritime casualty investigations, VDR data not properly safeguarded in the immediate aftermath of the event was partially or entirely lost through overwriting by the continuous recording cycle, depriving investigators of information potentially decisive to reconstructing the incident's dynamics.

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

What the PSCO Checks

Port State Control Officers (PSCOs) verify documentation of the last annual performance test of the VDR and, where possible, the operational functionality of the equipment; a non-functioning VDR is considered a significant deficiency given its relevance to investigations.

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.

Preparation checklist

Educational checklist. This summary supports learning and preparation only. It does not replace the vessel’s approved procedures, manuals, statutory documents, company SMS, or applicable official requirements. Completing it demonstrates neither compliance nor readiness for an inspection: it shows that a list has been read, not that the ship is in order. Always verify the current documents carried on board.

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 ships subject to the requirement: compliant electronic inclinometer or other means; VDR interface checked where an inclinometer is used

FAQ

What performance standard applies to recently installed VDRs?

VDRs installed from 1 July 2022 must comply with Resolution MSC.333(90), as amended by Resolution MSC.494(104).

For how many hours does a VDR retain data?

For VDRs: at least 12 hours before 1 July 2014; from 1 July 2014 at least 48 hours on fixed and float-free media and 720 hours on long-term media. For S-VDRs check MSC.163(78): at least 12 hours. Six-month retention after recording ends in the float-free capsule was already specified by MSC.333(90), not introduced in 2022.

How often must the VDR annual performance test be carried out?

Annually. SOLAS V/18.8 assigns it to an “approved testing or servicing facility” and gives it a precise object: to verify “the accuracy, duration and recoverability of the recorded data”. A copy of the certificate of compliance stays on board, and it is the document from which the applicable standard can be read.

What happens to VDR data if it is not safeguarded after an incident?

The recorder continues its recording cycle, progressively overwriting older data: without prompt saving to external media, information relating to the event can be permanently lost.

What does Resolution MSC.532(107) introduce and to whom does it apply?

It introduces SOLAS V/19.2.12: containerships and bulk carriers of at least 3,000 GT constructed on or after 1 January 2026 must have an electronic inclinometer, or other means, to determine, display and record roll motion.

VDR (Voyage Data Recorder)

Operational Explanation

How many hours, in fact: it depends on when the VDR was installed

After an incident: who saves the data, and with how much margin

Regulatory Reference

Scope of Application

Procedure / How to Complete It

Practical Example

What Typically Goes Wrong

Common Mistakes Mistake Library

What the PSCO Checks

Operational Tips

Preparation checklist

FAQ

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