Ask any captain, surveyor or flag-state examiner what they think of a sea service spreadsheet, and you'll get the same tired look. Not because crew are dishonest, almost none are, but because a spreadsheet proves nothing. Anyone can type "18 months, M/Y Aurora" into a cell. The document carries no evidence that the vessel existed, that you were aboard, or that the dates are accurate.
That gap costs crew real opportunities. It slows down certificate-of-competency applications, delays revalidations, and turns what should be a quick reference check into a week of chasing old captains for letters. This guide walks through what actually counts as sea service, why the spreadsheet era is ending, and how to produce a verified, audit-ready Digital Sea Service (DSS) report in about thirty seconds.
What actually counts as sea service
"Sea service" is a precise term, not a synonym for "time on a boat." Flag states and the STCW Convention recognise sea time only when it can be substantiated against specific criteria. Before you log anything, make sure each entry can answer these questions:
- Which vessel, and what was its tonnage and propulsion? Gross tonnage (GT) and kW propulsion power band determine which certificates the time counts toward.
- What was your rank or capacity? Time served as a deckhand counts differently from time as an officer of the watch.
- What were the exact join and leave dates? Sea service is counted in actual days aboard, not contract length.
- Was the vessel in commission and going to sea? Yard periods and lay-up often don't count, or count at a reduced rate, depending on the flag.
- Who can attest to it? A master, manager or recognised authority must be able to confirm the record.
If an entry can't answer all five, it isn't audit-ready, it's a claim. The whole point of a Digital Sea Service record is to attach evidence to each of those five answers before anyone asks for it.
Why STCW rest hours belong in the same record
Sea time and rest hours are usually tracked in two different places, sea time in a discharge book, rest hours in a separate logbook or app. That separation is a problem, because under STCW and MLC 2006 a watchkeeper must have a minimum of 10 hours of rest in any 24-hour period and 77 hours in any 7-day period. During a Port State Control or flag inspection, those rest-hour records are scrutinised alongside the sea service.
When the two live together, your record tells a complete, consistent story: you were aboard this vessel, for these dates, standing these watches, with rest hours that comply. Keeping them in one DSS record removes the contradictions that inspectors look for.
A discharge book proves you signed on and off. It does not prove your hours were compliant, or that the dates were never edited after the fact. Verification closes both gaps.
Why employers and surveyors distrust spreadsheets
It comes down to three structural weaknesses that no amount of careful formatting can fix:
- It's editable without a trace. A cell changed in 2026 looks identical to one entered in 2021. There's no audit trail, so there's no way to know what was altered.
- It's self-asserted. Every line is the crew member's own word with no counter-signature, no link to the vessel's records, and no third party standing behind it.
- It doesn't reconcile. Tonnage, dates and ranks rarely line up perfectly across a CV, a discharge book and a rest-hour log, and those mismatches are exactly what a surveyor flags.
A surveyor isn't questioning your honesty. They're questioning whether your evidence would survive an audit, and a spreadsheet never does.
How verification works via DSS
Digital Sea Service is the verification layer that turns self-reported sea time into evidence. Rather than trusting the entry, DSS attaches proof to it and reconciles the record against the documents that support it. In practice, three things happen behind a single record:
- Document matching. Each service period is linked to the documents that back it, discharge book pages, contracts, vessel particulars, and cross-checked for consistency.
- Counter-signature. A master or manager confirms the period, so the time carries a second signature rather than just yours.
- Tamper-evident history. Once verified, an entry is locked with a timestamp. Any later change is recorded, so a reviewer can see the record was never quietly edited.
The output is a report a surveyor can take at face value: every line shows who verified it and when, with the supporting evidence one click away.
Generate your report: step by step
Once your records are in YWC, producing an audit-ready report is fast. Here's the full flow:
- Add each service period. Enter the vessel, tonnage band, propulsion power, your rank, and exact join/leave dates. The vessel particulars autofill if the yacht is already in the registry.
- Attach evidence. Upload the discharge book page, contract or vessel document for each period. OCR reads the dates so you can confirm them in a tap.
- Import or log rest hours. Pull in your STCW rest-hour log so compliance sits alongside the sea time.
- Request counter-signature. Send a verification request to the master or manager. They confirm with one click; the period is then marked verified.
- Generate the report. Hit
Generate report. DSS reconciles every entry and produces a dated PDF plus a shareable verified link, typically in under 30 seconds.
From then on the report stays current. Add a new contract and regenerate; the new period slots in already evidenced.
Common mistakes to avoid
Most rejected sea service records fail for avoidable reasons. Watch for these:
- Rounding dates. "Roughly June to December" won't survive an audit. Use the actual sign-on and sign-off dates from your discharge book.
- Guessing tonnage. Tonnage band decides which certificate the time counts toward. Take it from the vessel's documents, never from memory.
- Overlapping periods. Two contracts that overlap by a day are an instant red flag. Reconcile them before you submit.
- Ignoring yard time. Lay-up and refit periods often count differently. Log them honestly and let the rules apply, rather than padding the total.
- Leaving verification to the last minute. Counter-signatures take time, and captains move on. Request them while the contract is still fresh.
Get these right once and your record becomes a living document you simply keep current, instead of a fire drill every time a surveyor asks for proof. If you want a deeper reference, our blog covers each step in more detail.