CMI Marine Accident Investigation Procedures 5 — Questions and Answers
Question 1: When calculating the speed of a vessel involved in a collision using ARPA/radar data preserved in a VDR, the investigator should account for which additional variable to obtain true speed over ground?
- Sea state and wave height at the time of the casualty
- Current set and drift experienced in the area at the time (Correct answer)
- The vessel's draft and trim condition
- Air temperature and barometric pressure
Correct answer: Current set and drift experienced in the area at the time
Speed through water (from radar/ARPA or log) differs from speed over ground; current set and drift must be added vectorially to determine the vessel's actual ground track.
Question 2: A 'near miss' or 'near accident' report is valuable to a marine safety investigator primarily because:
- It establishes prior negligence by the vessel operator for litigation purposes
- It reveals latent hazards and system weaknesses before they result in a catastrophic accident (Correct answer)
- It satisfies USCG mandatory reporting requirements under 46 CFR Part 4
- It provides grounds for immediate suspension of the vessel's Certificate of Inspection
Correct answer: It reveals latent hazards and system weaknesses before they result in a catastrophic accident
Near-miss data exposes the same causal factors and latent deficiencies that produce accidents, allowing corrective action before a fatality or major loss occurs.
Question 3: In marine fire casualty investigations, which piece of evidence is most useful for determining the fire's point of origin?
- Crew testimony about where smoke was first visible from the bridge
- Burn pattern analysis and char depth measurements within compartments (Correct answer)
- The fire detection system's alarm log showing the first activated sensor zone
- Comparison of the vessel's fire plan with observed damage locations
Correct answer: Burn pattern analysis and char depth measurements within compartments
Physical burn patterns and char depth measurements objectively trace fire propagation back to its origin point, supplementing (and sometimes correcting) witness accounts or sensor data.
Question 4: A vessel grounds on a charted shoal in clear weather. The investigation reveals the electronic chart display (ECDIS) was set to a raster chart with incorrect datum offset. This best illustrates which category of causal factor?
- Environmental factor
- Equipment/technology factor with human factors implications (Correct answer)
- Organizational regulatory compliance failure only
- Random mechanical failure
Correct answer: Equipment/technology factor with human factors implications
An ECDIS datum offset error is an equipment/technology factor, but its presence on the bridge without correction implicates human factors (training, watchkeeping, verification procedures) as well.
Question 5: When a marine investigator identifies a safety recommendation arising from a casualty investigation, what is the most critical quality standard that recommendation must meet?
- It must assign individual fault to a named mariner
- It must be specific, actionable, and directed at the party with authority to implement it (Correct answer)
- It must call for new legislation before any administrative action is taken
- It must be unanimously endorsed by all substantially interested states
Correct answer: It must be specific, actionable, and directed at the party with authority to implement it
Effective safety recommendations are specific and actionable, directed to the entity (operator, flag administration, IMO) actually empowered to make the identified change.
Question 6: Under the USCG marine investigation process, a 'formal investigation' (Marine Board of Investigation) is convened when:
- Any vessel over 26 feet is involved in a casualty resulting in injury
- A casualty involves loss of life, serious injury, major environmental damage, or significant public interest warranting a formal proceeding (Correct answer)
- Any commercial vessel casualty results in property damage exceeding $10,000
- A preliminary investigation cannot be completed within 30 days
Correct answer: A casualty involves loss of life, serious injury, major environmental damage, or significant public interest warranting a formal proceeding
A Marine Board of Investigation is convened for the most serious casualties — those involving loss of life, severe injuries, substantial pollution, or significant public interest — where a formal adversarial proceeding is warranted.
Question 7: The 'five whys' technique applied during a root cause analysis of a marine accident is intended to:
- Interview at least five witnesses to corroborate each finding
- Iteratively ask why each cause occurred until the root systemic cause is identified (Correct answer)
- Identify five separate causal factors for each accident event
- Ensure five regulatory bodies review the investigation findings
Correct answer: Iteratively ask why each cause occurred until the root systemic cause is identified
The 'five whys' method drills through successive symptom-level explanations by repeatedly asking 'why' until the underlying systemic root cause — often a policy, training, or design deficiency — is uncovered.
CMI Marine Accident Investigation Procedures 5
When calculating the speed of a vessel involved in a collision using ARPA/radar data preserved in a VDR, the investigator should account for which additional variable to obtain true speed over ground?