Ratings and specialist endorsements — what each one covers, refresher cycles.
What it is
A national maritime administration's certificate that a seafarer has completed a specific STCW course module — Basic Safety Training (A-VI/1), PSCRB (A-VI/2-1), Advanced Fire Fighting (A-VI/3), Medical First Aid (A-VI/4-1), Security Awareness (A-VI/6-1), Designated Security Duties (A-VI/6-2), or tanker / passenger-ship endorsements.
Who needs it
Every seafarer — different sets depending on rank, vessel type, and route.
When it is checked
Sign-on muster.
Port-state-control safety inspection.
Drills and audits.
Common mistakes
Letting refreshers lapse — PSCRB and AFF require 5-yearly refreshers under the 2010 Manila Amendments.
Mixing up CoP code numbers with the STCW table reference — write both on your CV.
Validity
Typically 5 years, with refresher requirements for PSCRB, AFF, MFA, and tanker endorsements.