FerryFetch counts a sailing as on time when it arrives within 5 minutes of schedule, measured from the vessel's live AIS position, and publishes an on-time rate only once 30 or more completed sailings back it.
A sailing is on time when it stays within 5 minutes of its published schedule, both leaving and arriving. FerryFetch measures this from the vessel's own AIS position, not from the timetable.
An on-time rate is the share of completed sailings over the last 30 days that were never more than 5 minutes behind schedule. Cancelled sailings are counted separately and are left out of the on-time rate. A rate is only published once at least 30 completed sailings sit behind it; below that the page shows no rate instead of a number built on too few sailings.
A sailing counts as delayed once its estimated or actual arrival is more than 5 minutes behind schedule. The estimate comes from the vessel's live position and speed, so a delay can show on FerryFetch before the operator posts a notice. Each estimate carries a HIGH, MEDIUM or LOW confidence label based on how fresh and steady the vessel's signal is.
Cancelled means the operator has cancelled one sailing. FerryFetch takes cancellations from the operator's published service information and never infers one from a missing signal.
Not running means a whole route is out of service for now, for example a seasonal break or a suspension the operator has announced. The route page stays up with its service status and related routes to check instead.
Ferries broadcast their AIS position every few seconds while under way, and far less often while tied up at a berth. The live tracker map asks for a fresh position every 15 seconds while you follow a ferry. Route, terminal and operator pages refresh their live data about once a minute and show when it was last updated.
When a vessel's signal drops out, FerryFetch keeps its last known position labelled with how old it is, and says the sailing is still expected. It never moves a ferry to a guessed position.
Vessel positions come from AIS (Automatic Identification System), the radio signal every passenger ferry broadcasts. Schedules come from each operator's published timetables, with holiday and seasonal exceptions applied. Cancellations, service notices and, where an operator publishes them, live feeds such as deck space are read from the operator's own public information.
Which vessel runs a sailing is confirmed only from AIS evidence. When FerryFetch predicts the vessel ahead of time, the prediction is labelled as one and expires; it never creates a vessel page.
FerryFetch is independent and not affiliated with any ferry operator. Figures can differ from an operator's official service information, which stays the authority on cancellations.