Fisheries VMS Domain · Lesson 10 of ∞ · Second pass · ← Lesson 9

Second pass · the half e-Boat doesn't own, in detail

Inside an electronic logbook: what ERS actually records

Lesson 6 established that eFish owns catch reporting so e-Boat doesn't have to. This lesson goes one level deeper into what that reporting actually looks like — useful the moment a real eFish payload lands on your desk.

An ERS (Electronic Reporting System) replaces the paper fishing logbook with structured messages sent during a trip rather than a story reconstructed afterward. The EU's ERS — the most mature, best-documented implementation, and the one Ukraine's reform visibly takes cues from — is built around a small set of message types, each covering one moment in a trip's life:

MessageWhat it recordsWhen
DEP (Departure)Vessel leaving port, gear on board, intended areaBefore fishing starts
CAT / DCA (Catch)Species and quantity caught, by fishing operationDuring the trip, per haul or per day
TRA (Transhipment)Catch moved to another vessel at seaIf/when it happens
COX / COE (Entry/exit of an area)Crossing into or out of a regulated zoneOn crossing
POR (Prior notification)Advance notice of intent to land, for port-side inspection planningBefore landing
EOF (End of Fishing)Declares the trip's catch record final — the logbook cannot be corrected after this messageEnd of trip

Source: Electronic Reporting System — overview, ISSF glossary — ERS.

The detail worth remembering

EOF is a one-way door. Once a trip's logbook is finalised, it's evidence, not a draft — any post-hoc correction has to happen through a separate, auditable amendment process, not by editing the original record. This is the same instinct behind e-Boat's own violation history requirement (C-052..C-065): a record of what was detected, and when, has to survive even if the underlying understanding changes later.

The declaration that closes the loop: landing

Separate from the logbook itself, a landing declaration — what was actually brought ashore — must typically be submitted within a fixed window after landing (24 hours, in the EU system). This is the number that gets cross-checked against the logbook's catch messages. A mismatch here is the concrete, operational form of the "Unreported" IUU failure mode from Lesson 2: not a missing report, but two reports that don't agree.

Why this matters for reading e-Boat's boundary correctly

e-Boat has no DEP/CAT/EOF messages of its own — that vocabulary lives entirely on the eFish side. What e-Boat contributes to this picture is independent: a position and geofence record that exists whether or not the vessel ever files a logbook message at all. The genuinely useful capability — one neither system has alone — is the cross-check: does the vessel's declared activity (eFish) match its observed activity (e-Boat)? That comparison is exactly the kind of analysis the C-127..C-133 integration boundary exists to make possible, even though building the comparison logic itself isn't explicit in the current ToR scope.

Check your recall

Something unclear, or want to go deeper on any term here? Ask the agent that built this lesson — it's your teacher for this workspace, not just a lesson generator.