Start hereRules checked 20 October 2026
On 1 October 2015 the cargo ship El Faro sailed into Hurricane Joaquin and sank with all 33 people on board. Ten months later a US Navy remotely operated vehicle lifted her VDR capsule from 15,250 feet below the surface. It held more than 26 hours of bridge audio from six microphones, radar images and ship’s data, and it let the National Transportation Safety Board reconstruct the last day on the bridge minute by minute. It also exposed a sensor fault that had gone unrepaired: the officers had remarked that the anemometer was not working, and the wind data the VDR had recorded were wrong.
That is what the VDR annual performance test is for: once a year an approved technician proves that every required input reaches the recorder, that recording survives a power loss, that the capsules can be found and the data read back. A sensor that has been dead for months should be caught here. This lesson walks through the test as it happens on board.
Try it
A VDR annual performance test from planning to certificate
In plain words
A voyage data recorder is the ship’s “black box”. It records position, speed, heading, the radar picture, what was said on the bridge and on VHF, engine and rudder orders, alarms and door status. It keeps the data in tough capsules: one fixed to the ship that resists fire, impact and deep water, and on newer installations one that floats free if the ship sinks and sends a homing signal.
The data are only useful if every input reaches the recorder, and sensors fail quietly: a microphone dies, a junction box is disconnected in a refit, a new ECDIS is never connected. So once a year a technician approved for that make of VDR removes the power to prove the backup battery lasts two hours, tests the underwater locator beacon, checks the capsules and records 12 hours of data. The manufacturer analyses those 12 hours, confirms every required item was recorded and issues a certificate, which the ship keeps on board.
In detail
The legal basis
SOLAS regulation V/20 says which ships carry a VDR, and V/18.8 requires the annual test by “an approved testing or servicing facility”. The method is in MSC.1/Circ.1222/Rev.1 (June 2019), which replaced the 2006 circular and says the test should be done by the manufacturer or a person it authorises. Approval of the facility comes from the flag or from class acting for it, usually under IACS UR Z17.
What is checked, item by item
The annex, paragraph 2, lists eight checks. The model test report in its appendix turns them into tick boxes.
| Check (Circ.1222/Rev.1 annex 2) | What the technician does |
|---|---|
| .1 No pre-existing alarms | Confirms the system is healthy before starting |
| .2 Power supply and reserve power | Removes external power; alarm must sound; recording must continue for at least 1 h 55 min and stop automatically no later than 2 h 5 min |
| .3 Acoustic beacon | Tests the underwater locator beacon with the manufacturer’s test set, or fits a certified fully operational replacement |
| .4 Condition and batteries | Inspects main unit, capsule and cables; records expiry dates of beacon and reserve power batteries |
| .5 Maintenance records | Confirms accurate VDR maintenance records exist |
| .6 Data items over 12 hours | Confirms all items required at commissioning are stored for the 12-hour period |
| .7 Float-free capsule | Checks float-free arrangements, release mechanism and battery expiry dates; for MSC.333(90) capsules, examines it as for a float-free EPIRB under MSC.1/Circ.1040/Rev.1 |
| .8 Restore normal mode | Confirms the VDR is back in normal operation |
Know the interfaces in the model report, because each is a possible gap: date and time, position, speed, heading, bridge audio, VHF audio, radar (both radars where applicable), ECDIS, AIS, rolling motion, configuration data, electronic logbook, depth, mandatory bridge alarms, rudder and engine orders and responses, hull opening, watertight and fire door status, hull stress and wind (where fitted).
Why 2 hours, and why 12 hours
Under MSC.333(90), after a power failure the VDR records bridge audio from its reserve source for 2 hours, then stops automatically; the 1 h 55 min to 2 h 5 min window allows for timing tolerance. The 12 hours is only the sample analysed: a VDR installed from 1 July 2014 keeps all data for at least 30 days on the long-term medium and 48 hours in the capsules. The UK MCA adds that the 12-hour data should be recorded as close as practicable before the certificate is issued.
Which performance standard applies
Your VDR is tested against the standard it was approved to, which depends on the installation date:
| Installed | Performance standard |
|---|---|
| Before 1 June 2008 | Resolution A.861(20) |
| 1 June 2008 to before 1 July 2014 | A.861(20) as amended by MSC.214(81) |
| 1 July 2014 to before 1 July 2022 | MSC.333(90) |
| On or after 1 July 2022 | MSC.333(90) as amended by MSC.494(104), which aligns the float-free capsule with the float-free EPIRB standard4 |
Older cargo ships fitted with a simplified VDR (S-VDR) under the 2006 phase-in are tested to the S-VDR standard, resolution MSC.163(78).
When it is due
The test is aligned with the HSSC surveys: up to 3 months before the due date for a passenger ship, or 3 months either side for a cargo ship, giving at most 15 or 18 months between tests (more only if a certificate is extended under SOLAS I/14). IACS members require it within the survey window and no later than completion of the survey.
The 45-day rule and the certificate
The manufacturer must review the test and issue the completed report within 45 days; if it does not, the model report says the test report “should go forward for certification”. Tip for masters: keep the technician’s signed report on board and diary the 45-day date to chase the certificate.
What the rules say
- SOLAS regulation V/18.8 requires the VDR system, “including all sensors”, to have an annual performance test by an approved testing or servicing facility, verifying the accuracy, duration and recoverability of the data, with tests of protective enclosures and location aids, and a copy of the certificate of compliance kept on board.2
- MSC.1/Circ.1222/Rev.1, annex paragraph 1, says the annual test should be carried out by the manufacturer or a person authorised by the manufacturer.1
- MSC.1/Circ.1222/Rev.1, annex paragraph 2.2, requires confirmation that when external power is removed the alarm activates, the equipment operates for at least 1 h 55 min and stops recording no later than 2 h 5 min after.1
- MSC.1/Circ.1222/Rev.1, annex paragraph 3, requires the manufacturer to complete its review and issue the completed test report within 45 days, and allows the test up to 3 months before the due date (passenger ships) or within 3 months either side (cargo ships).1
- IACS UI SC279 interprets the timing so that the VDR test is done within the HSSC survey time window and no later than completion of the survey for endorsement or renewal of the certificate.2
- Resolution MSC.333(90), paragraph 5.4, requires a VDR to keep recording bridge audio for 2 hours from its reserve power source after a power failure, and to keep all data for at least 30 days on the long-term medium and 48 hours on the fixed and float-free media.3
- The HSSC Survey Guidelines, 2025, paragraph (EA) 1.2.2.38, have the surveyor check “the provision, specification, operation and annual performance test of the voyage data recorder” at each annual survey.6
Flag and class notes
- IACS UR Z17. Class approves VDR test firms as service suppliers under UR Z17, which requires evidence that the firm is authorised by the manufacturer for each make and model. A manufacturer applying MSC.1/Circ.1222 in full may itself be the approved supplier and appoint authorised service stations, which need not be separately approved; it then reviews their reports and 12-hour logs and issues the certificates.7
- United Kingdom. MGN 272 (M) requires the test to be done by a competent person accredited by the equipment manufacturer, an EU flag State or a UK authorised classification society, independent of the owner unless the test is witnessed by an MCA surveyor. It also advises switching off the VDR shortly after arrival if needed to stop the 12-hour data being overwritten.5
- Singapore. MPA Shipping Circular No. 9 of 2006 says the approved facility must be the manufacturer’s own facility or one it has authorised, and that an authorised third-party facility must be accepted by one of the classification societies recognised by MPA.8
- Other flags. Many flags publish their own VDR circulars. Check your flag’s list of accepted facilities before booking, and ask the technician for the evidence of manufacturer authorisation and class approval required by UR Z17.7
Key numbers
| What | Value |
|---|---|
| Reserve power: still recording at | 1 h 55 min after external power is removed1 |
| Reserve power: recording stopped by | 2 h 5 min1 |
| Data sample analysed by the manufacturer | 12 hours1 |
| Manufacturer’s review and final report | within 45 days1 |
| Test window, passenger ship | up to 3 months before the due date (max. 15 months between tests)1 |
| Test window, cargo ship | 3 months either side of the due date (max. 18 months between tests)1 |
| Data retention, long-term medium (MSC.333(90)) | at least 30 days / 720 hours3 |
| Data retention, fixed and float-free capsules | at least 48 hours3 |
What inspectors find
- VDRs that do not record everything. In the 2017 Tokyo MOU campaign on safety of navigation, 74 of 6,013 ships (1.2%) could not show that their VDR or S-VDR recorded data fully.9
- Bad sensor data that nobody noticed. On El Faro, the VDR captured wind data from an anemometer the officers knew was broken; investigators found the recorded wind data inaccurate.10
- Missing or out-of-date certificate. The certificate of compliance is on the IMO list of documents a PSC officer checks, and “absence or failure of a voyage data recorder (VDR), when its use is compulsory” is a possible ground for detention.11
- Batteries. Beacon and reserve power battery expiry dates are a separate line on the test report, so check them between tests too.1 El Faro’s last annual test, in December 2014, noted that the beacon battery would expire in May 2015, before the next test, yet the certificate was issued without it being replaced; no beacon signal was detected in the first underwater search.10
FAQ
Can the ship's electro-technical officer do the annual test?
Not on their own: SOLAS V/18.8 requires an approved facility, and the circular expects the manufacturer or a person it authorises. The crew keep the maintenance records and do the routine checks in the manual.
We changed the ECDIS. Does the VDR need retesting?
Record the change in the VDR maintenance records; the test report has sections for “change or repair of sensors” and significant events since the last test. Ask the VDR service company whether it needs a configuration update and check now rather than at the next annual test.
Does the test download the data for the owner?
The test analyses a 12-hour sample to prove the recording works. It is not an incident download. After an incident, data should be saved by the crew as the manufacturer’s instructions describe and handed to the investigating authority.
Quiz6 questions
Sources
- 1
IMO MSC.1/Circ.1222/Rev.1, Guidelines on annual testing of voyage data recorders (VDR) and simplified voyage data recorders (S-VDR) (14 June 2019), paragraph 4 and annex paragraphs 1 to 4 and appendix (model test report). https://wwwcdn.imo.org/localresources/en/OurWork/Safety/Documents/IMO%20Documents%20related%20to/MSC.1-Circ.1222-Rev.1.pdf
- 2
SOLAS 1974, as amended, regulation V/18.8, and IACS Unified Interpretation SC279, Annual testing of VDR, S-VDR, AIS and EPIRB (June 2016, applied by IACS members from 1 July 2017), which reproduces the regulation and gives the interpretation of timing. https://iacs.org.uk/
- 3
IMO Resolution MSC.333(90), Adoption of revised performance standards for shipborne voyage data recorders (VDRs) (adopted 22 May 2012), operative paragraph 2 and annex paragraphs 5.2 and 5.4. https://wwwcdn.imo.org/localresources/en/KnowledgeCentre/IndexofIMOResolutions/MSCResolutions/MSC.333(90).pdf
- 4
IMO Resolution MSC.494(104), Amendments to the performance standards for shipborne voyage data recorders (VDRs) (resolution MSC.333(90)) (adopted 7 October 2021), operative paragraph 2. https://wwwcdn.imo.org/localresources/en/KnowledgeCentre/IndexofIMOResolutions/MSCResolutions/MSC.494(104).pdf
- 5
Maritime and Coastguard Agency, MGN 272 (M), Voyage Data Recorders (VDRs) – Performance Testing (July 2004), paragraphs 2, 4 and 5. https://assets.publishing.service.gov.uk/media/5f6b0ba6d3bf7f7237cf3fba/mgn272.pdf
- 6
IMO Resolution A.1207(34), Survey Guidelines under the Harmonized System of Survey and Certification (HSSC), 2025, annex, paragraphs (EI) 1.1.4.34–1.1.4.35 and (EA) 1.2.2.38. https://wwwcdn.imo.org/localresources/en/OurWork/IIIS/Documents/A%2034-Res.1207%20-%20SURVEY%20GUIDELINES%20UNDER%20THE%20HARMONIZED%20SYSTEMOF%20SURVEY%20AND%20CERTIFICATION%20(HSSC),%202025%20(Secretariat).pdf
- 7
IACS Unified Requirement Z17, Procedural requirements for service suppliers, annex 1, section on firms engaged in annual performance testing of voyage data recorders (VDR) and simplified voyage data recorders (S-VDR) (text read: Rev.11, 2015; check the current revision on the IACS website). https://iacs.org.uk/
- 8
Maritime and Port Authority of Singapore, Shipping Circular No. 9 of 2006, Annual performance test for voyage data recorder (VDR) (24 April 2006). https://www.mpa.gov.sg/media-centre/details/no-9-of-2006---annual-performance-test-for-voyage-data-recorder-(vdr)
- 9
Tokyo MOU, Report of the 2017 Concentrated Inspection Campaign on Safety of Navigation, including ECDIS (November 2018), Table 1, question 5. https://www.tokyo-mou.org/wp/wp-content/uploads/CIC-Safety-of-Navigation-including-ECDIS-Report-p.pdf
- 10
National Transportation Safety Board, Sinking of US Cargo Vessel SS El Faro, Atlantic Ocean, Northeast of Acklins and Crooked Island, Bahamas, October 1, 2015, Marine Accident Report NTSB/MAR-17/01 (2017), abstract and sections 1 and 1.3.10 (Electronic Equipment). https://www.ntsb.gov/investigations/AccidentReports/Reports/MAR1701.pdf
- 11
IMO Resolution A.1206(34), Procedures for port State control, 2025 (adopted 3 December 2025), appendix 2, section 5, item 17, and appendix 12, item 41. https://wwwcdn.imo.org/localresources/en/KnowledgeCentre/IndexofIMOResolutions/AssemblyDocuments/A.1206(34).pdf
Rules checked 20 October 2026. VSL Safety is not an approved training provider and doesn't issue certificates. These lessons don't replace STCW training, or the manufacturer's training and certification that service technicians need.
