M3000-3.5.12

Reports required by the MAIB

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Why the MAIB Exists — and Why You Must Report

The Marine Accident Investigation Branch exists to improve safety, not to apportion blame. Its legal foundation is the Merchant Shipping (Accident Reporting and Investigation) Regulations 2012 (SI 2012/1743), which implement the EU/IMO framework for independent investigation. The MAIB is entirely separate from the MCA; a report to the MAIB is not a confession to a regulator — but failure to report is a criminal offence under the Regulations.

As Master, the duty to report falls on you. If you are incapacitated, it passes to the owner or operator. Understanding this chain of responsibility matters in the oral because the examiner is testing whether you see yourself as the accountable party.

What Must Be Reported

The Regulations distinguish three categories:

Very Serious Marine Casualty — total loss, loss of life, or severe structural damage. Must be reported to the MAIB immediately (as soon as practicable; in practice, by the fastest available means — telephone first, then written confirmation).

Serious Casualty — significant structural damage, fire, explosion, collision, grounding, contact, capsizing, flooding, or an injury requiring hospitalisation but not loss of life. Report immediately.

Less Serious Casualty / Marine Incident — an occurrence that, under different circumstances, could have become a casualty; includes near-misses that are reportable. These are reported on the MAIB's standard form (Report of an Accident or Incident to a Vessel — Form MCA 8523 or equivalent) within a reasonable time, typically taken as no later than 7 days.

Personal Injury — if a person is incapacitated for more than three days (not counting the day of the accident), a written report is required.

Death on board — always reportable, regardless of cause.

Application on a Superyacht

MSN 1858 defines the certification and manning framework that determines which vessels fall within the UK scheme. As Master of a UK-registered yacht (or a foreign yacht in UK waters where the UK is the flag state or investigation state), you are in scope under the Merchant Shipping (Accident Reporting and Investigation) Regulations 2012.

In practice: after securing safety, your immediate sequence is — telephone the MAIB duty officer (24-hour number, carried in your emergency contacts), preserve evidence (VDR/SVDR data, charts, logs, photographs), and make no repairs that would destroy evidence without MAIB consent. The MAIB may instruct you to hold the vessel.

Crucially: do not conflate MAIB reporting with MCA Port State or casualty reporting obligations — both may apply concurrently.

The Master's Decision

In the oral, the examiner wants to see that you classify the event correctly, report without delay, preserve evidence, and understand that the MAIB investigation is conducted independently of any regulatory action. Your log entries should record what happened and what you reported, and when.

Practice questions

recallcore

Under UK law, who is primarily responsible for reporting a marine accident to the MAIB?

recallcore

What are the three categories of reportable occurrence under the MAIB Regulations, and how does the required speed of reporting differ between them?

scenariocore

At 0300 your 499 GT motor yacht grounds on a charted shoal in the Solent. There is hull damage; the bilge pump is running but flooding is controlled. All crew are safe. What are your immediate reporting obligations regarding the MAIB, and what must you not do before they respond?

oralstretch

You're the Master of a 1,200 GT superyacht. A crew member falls down a companionway ladder during a night passage. He has a suspected fractured wrist and is evacuated by helicopter to hospital the following morning. Do you have a duty to report this to the MAIB? Walk me through your reasoning and what you do.

scenariostretch

During a charter passage, a guest slips on deck and grazes their knee. They are treated with first aid on board and are not hospitalised. Your chief officer asks whether this needs to go to the MAIB. What is your answer, and what records do you make?

Independent preparatory study aligned to the MCA Master (Yachts less than 3000 GT) examination syllabus (updated June 2026). Not an MCA-approved course and confers no credit toward a Certificate of Competency.