How do STCW and MLC 2006 align on seafarer medical certificates, and what validity periods apply?
Short answer
| Certificate | Validity |
|---|---|
| Medical certificate | maximum two years |
| Seafarer under 18 | one year |
| Colour vision certification | six years |
| Expired at sea, urgent case | to the next port with a recognised practitioner, at most three months |
- One certificate serves both: MLC Standard A1.2 §3 is without prejudice to STCW; a medical certificate issued under STCW is accepted for MLC Regulation 1.2.
- STCW I/9 and A-I/9: fitness standards, the eyesight table A-I/9, recognised practitioners on a register, an appeal process and the minimum certificate content.
- Validity (A1.2 §7): maximum two years; one year when the seafarer is under 18; colour vision certification six years.
- Grace (A1.2 §8, STCW A-I/9): in urgent cases a recently expired certificate is honoured only to the next port with a recognised practitioner, not beyond three months.
- Why harmonise: the 2010 Manila amendments dovetailed STCW with MLC so one valid certificate serves both instead of two overlapping regimes.
- As Chief Engineer: nobody joins or sails on a lapsed medical (India: DGMA-approved practitioners, MS Act 2025 s.57 and s.46); a lapse at sea is honoured only to the next port.
Full answer
The full answer explains each point step by step, with the regulations and figures behind it and the discussion from other candidates. It is in the MEO Class I section of the Marine One forum, open to members enrolled for the MEO Class I exam.