Answer
The Casualty Investigation Code (IMO Resolution MSC.255(84), Part I, Chapter 2) explicitly defines three statutory categories of maritime occurrences: Very Serious Marine Casualty, Marine Casualty, and Marine Incident.
| Category | CIC Regulation | Statutory Definition (MSC.255(84)) |
| Very Serious Marine Casualty | Chapter 2, Para 2.22 | A marine casualty involving: • Total loss of the ship (or presumed loss / abandonment). • A death (loss of life). • Severe damage to the environment (as defined in Para 2.19). |
| Marine Casualty | Chapter 2, Para 2.9 | An event, or sequence of events, occurring directly in connection with ship operations that results in: • Death or serious injury to a person. • Loss of a person from a ship. • Loss, presumed loss, or abandonment of a ship. • Material damage to a ship. • Stranding or disabling of a ship, or involvement in a collision. • Material damage to external marine infrastructure (that imperils safety). • Severe damage to the environment (or potential severe damage) caused by ship damage. |
| Marine Incident | Chapter 2, Para 2.10 | An event or sequence of events, other than a marine casualty, occurring directly in connection with ship operations whereby: • The ship or any person is imperilled, OR • Serious damage to the ship, structure, or marine environment might be caused if not corrected (hazardous events / near-misses). |
Under IMO Circular MSC-MEPC.3/Circ.4 (Revised Harmonized Reporting Procedures – Reports Required under SOLAS Regulation I/21 and XI-1/6, and MARPOL Articles 8 and 12), occurrences are categorized into four distinct levels of severity for reporting to the IMO Global Integrated Shipping Information System (GISIS) database:
Categories of Marine Casualties and Incidents| Casualty Category | Specific Definition & Criteria |
| Very Serious Marine Casualty | A casualty involving a ship that results in: • The total loss of the ship (or loss/abandonment). • Loss of life. • Severe damage to the environment (severe pollution). |
| Serious Marine Casualty | A casualty that does not qualify as a Very Serious Casualty, but involves events such as fire, explosion, grounding, contact, heavy weather damage, ice damage, hull cracking, or suspected hull defect, resulting in: • Structural damage rendering the ship unseaworthy (e.g., underwater hull penetration, main engine immobilization, extensive accommodation damage). • Pollution (regardless of quantity). • A breakdown necessitating towage or shore assistance. |
| Less Serious Marine Casualty (or Marine Casualty) | An event directly connected with the operation of a ship (not qualifying as Very Serious or Serious) that results in: • Death or serious injury to a person (incapacitation > 72 hours starting within 7 days of injury). • Loss of a person from the ship (man overboard). • Material damage to the ship or external marine structure. • Stranding or disabling of the ship, or involvement in a collision. |
| Marine Incident | An occurrence or sequence of events, other than a marine casualty, occurring directly in connection with the operations of a ship whereby: • The ship or any person is imperilled. • Serious damage to the ship, structure, or marine environment might be caused if not corrected (hazardous events / near-misses). |