# Detect tampered and deepfake Seaman's Book > A seaman's book is an identity document and a career record bound together: it identifies the holder as a seafarer to a flag state, and its inner pages record every ship served on, with dates signed and stamped by the master. Both halves attract forgery. The identity pages are altered to give someone a seafarer's transit rights, and the service pages are padded to manufacture the sea time a certificate of competency requires. TamperCheck examines both. **Canonical URL:** https://tampercheck.ai/documents-support/seamans_book **API document class:** `seamans_book` --- ## What a genuine seaman's book contains The personal pages carry the seafarer's full name, date and place of birth, nationality, the book number in the issuing maritime authority's series, the date and place of issue, the expiry date, the issuing authority itself, the rank or capacity, a photograph and a specimen signature. Many books add height, eye colour and distinguishing marks. The remaining pages are the service record: one entry per engagement, with the vessel's name, flag and official or IMO number, the rank served in, the dates of sign-on and sign-off, and the master's signature over the ship's stamp. The two halves check each other, and the passport checks both. Name, date of birth and nationality must be identical to the passport presented with the book, and the photograph must be the same person from the same period. Service entries have to run in unbroken chronological order, with no seafarer serving two vessels at once, and each vessel's IMO number is a seven-digit figure with its own check digit that has to correspond to the ship named beside it. A rank in the service record above the capacity endorsed on the personal page is a contradiction the book makes about itself. ## How seaman's book forgeries are made ### Photograph substitution The photograph is lifted and replaced so a genuine book is used by someone else. The image sits under a laminate and usually behind a stamp or perforation crossing its edge, so a substitution leaves a laminate boundary, a stamp that no longer continues across the join, and a colour and noise profile unlike the page around it. ### Service entries added for sea time Engagements the seafarer never served are written into the record to reach the sea-time threshold for a higher certificate. Added entries use ink and a stamp that do not match the surrounding pages, and they frequently overlap the dates of an engagement already recorded two pages earlier. ### Expiry date extension A single digit moves a lapsed book back into validity. The altered figure rarely matches the character spacing of the issue date printed beside it, and the extension often produces a validity period longer than the issuing authority grants for that class of document. ### Book number and authority fabricated A book is presented from an authority the holder has no connection to, numbered in roughly the right shape. Maritime administrations issue in defined series and maintain registers they will confirm against, which is why the number is the field a shipping company checks first. ### Master's stamp reproduction Ship stamps are scanned from one page and reapplied to others. A wet stamp varies in ink coverage, catches the texture of the page and overlaps the handwriting beneath it; the copied version repeats at identical rotation and density in every entry that uses it. ### Complete counterfeit books Whole books produced with the cover, the numbering and the security printing imitated. These are assessed on substrate and print technology rather than on content, because intaglio, microtext and the way security print sits in the paper are not reproduced by an office printer. ## What TamperCheck checks on a seaman's book TamperCheck runs 200+ forensic checks across three layers and returns a risk score from 0 to 100 with plain-English findings tied to specific regions of the document. These three carry the most weight on this document class. ### Portrait substitution and face-swap analysis The document is isolated from whatever it was photographed on, then the portrait region is assessed against the card surface around it. A pasted or generated face rarely matches the substrate it was placed onto. ### Signature forgery analysis Signature regions are assessed for ink consistency and for how the stroke sits on the page, which distinguishes a genuine pen stroke from a pasted image of one. ### Date and validity consistency Issue, expiry, and period dates are checked against one another and against the file's own creation metadata, which catches backdating and validity extension. ### And many more checks The three above are the layers that carry the most weight on a seaman's book. Every upload runs the full suite of 200+ checks regardless of document class, spanning file structure and metadata, pixel-level forensics, font and text rendering, optical and print characteristics, provenance signals, AI-generation signatures, and many more checks. ## Who verifies a seaman's book, and why Shipping companies and consulates processing seafarer visas and crew changes. In each case the document is being used to unlock money, access, or a legal status, which is exactly what makes it worth forging. ## How to verify a seaman's book in 4 steps 1. **Check the book number with the issuing maritime authority.** Administrations keep a register of seafarer identity documents and will confirm whether a number was issued, to whom, and whether it remains valid. This is the check that settles a fabricated book, and the shipping company is usually best placed to make it. 2. **Read the service record against the vessels.** Each entry names a ship with a flag and an IMO number. Confirm the seven-digit IMO number passes its check digit and belongs to the vessel named, and that sign-on and sign-off dates do not overlap another engagement recorded in the same book. 3. **Compare the personal page with the passport.** Name, date of birth, nationality and the photograph should match the passport presented alongside the book, and both should match the seafarer identified in the shipping company's invitation letter and in the crew list. 4. **Run a forensic check on the photo page and the entries.** TamperCheck runs 200+ forensic checks over a scanned page, the photo zone included, and returns a risk score from 0 to 100 in about a minute, with each finding mapped to the region of the page it came from. ## Frequently asked questions ### How do I verify a seaman's book? Start with the book number and the issuing maritime authority, which maintains a register and will confirm whether the document was issued and to whom. Then read the service record: each entry's vessel should match its IMO number, sign-on and sign-off dates should not overlap, and the ranks should build into a plausible career. Finally compare the personal page against the seafarer's passport. ### Can a CDC be forged? Yes. Continuous discharge certificates are forged three ways: the photograph is replaced so a genuine book is used by another person, service entries are added to manufacture the sea time a higher certificate requires, and complete counterfeit books are produced with imitated security printing. The first two are alterations to a real document, and they are what a forensic examination is best placed to find. ### What is recorded in a seaman's book? The personal pages record name, date and place of birth, nationality, book number, issue and expiry dates, issuing authority, rank, photograph and specimen signature. The service pages record each engagement: the vessel's name, flag and IMO number, the capacity served in, the sign-on and sign-off dates, and the master's signature over the ship's stamp. ### Why does recorded sea time matter so much? Because certificates of competency are granted against recorded sea service, so the service pages carry direct commercial value. A few added months can move a seafarer into a rank they have not earned and should not hold at sea, which is why entries are compared against each other for overlapping dates and against the vessels they name. ## Related document types - Invitation Letter: https://tampercheck.ai/documents-support/invitation_letter - Sponsor Letter: https://tampercheck.ai/documents-support/sponsor_letter - Travel Itinerary: https://tampercheck.ai/documents-support/travel_itinerary - Travel Agency Booking: https://tampercheck.ai/documents-support/travel_agency_booking - Accommodation Booking: https://tampercheck.ai/documents-support/accommodation_booking - Host Accommodation Form: https://tampercheck.ai/documents-support/host_accommodation_form --- Try TamperCheck now: https://tampercheck.ai/dashboard · Docs: https://tampercheck.ai/docs · Pricing: https://tampercheck.ai/pricing