The national seafarer's discharge book or ILO C185-compliant Seafarer's Identity Document — what it proves, who issues it, validity, and replacement if lost.
What it is
A government-issued booklet (or biometric card) that identifies you as a seafarer, records your sea service, and — under ILO Convention 185 — allows shore leave at ratifying states without a transit visa. The most common formats are the Philippine SIRB, Indian CDC, Indonesian Buku Pelaut, Ukrainian seaman's record book, UK Discharge Book, and the post-2003 ILO C185 SID issued by ratifying administrations.
Who needs it
Every seafarer signing on to a commercial vessel. Even where a national CDC or SIRB is not the formal SID under ILO C185, it is treated as the de-facto seafarer's identity document by employers, agents, and most port-state authorities.
When it is checked
Manning-agency intake before the offer is finalised.
Airport check-in (airlines often want to see it together with the travel letter).
Immigration on arrival at the joining country.
Master sign-on muster onboard.
Port-state-control crew document check.
Sign-off — the Master endorses your discharge stamp, which becomes your sea-time evidence.
Common mistakes
Letting it expire while at sea — most CDCs run 5–10 years; renew before you next sign on, not after.
Missing a sign-off endorsement — without it, the contract is not provable for STCW sea-time.
Sending the original to a recruiter — never let an unverified agency hold an original document.
Treating the CDC as a passport replacement — it identifies you as a seafarer, it does not replace a passport for general travel.
Validity
Typically 5–10 years depending on issuing administration. ILO C185 SIDs are usually 10 years.
If lost or expired
Report immediately to the local police (if lost) and contact your flag-state administration or national maritime authority for replacement. Most administrations require an original police report, passport, photographs, and a fee. Sign-on without a CDC is rarely possible — your employer will usually defer joining until the replacement is issued.
Printable checklist
Original CDC / SIRB / SID in hand.
Validity at least 6 months beyond contract end (employer policy varies).
Last discharge endorsement legible.
Photocopy + phone-photo backup kept separately from the original.