Danish AIS historical data

Danish AIS historical data

The Danish Maritime Authority's shore-based AIS network publishes continuously updated historical AIS data for Danish waters as zipped daily CSV files, free to download with no account or key. Responsibility for the AIS-data mailbox now sits with Safety of Navigation, National Waters at the Danish Emergency Management Agency (Beredskabsstyrelsen), reflecting a reorganization since the data was first published.

Coverage

Daily zip archives (named by date) covering Danish waters, with monthly archives for earlier years and daily files from 2024-03-01 onward at roughly 600 MB compressed per day, published a few days after the data day. The source page states access is "continuously updated." No numeric retention limit, update-time guarantee or licence is stated on the page; access is governed by Denmark's public-sector-information (PSI) act, and the Danish Maritime Authority disclaims liability for errors, delays or interruptions in the data.

Verdict

This is a dense, ground-truth AIS feed for Danish and nearby waters, useful for validating or supplementing lower-resolution global AIS products around a major European shipping chokepoint (the Danish straits). The free historical files carry no stated reuse licence and an explicit disclaimer of accuracy and availability, and data must not be combined in ways that re-identify individuals without a Danish Data Protection Agency permit. Treat it as raw AIS needing your own parsing and quality checks, not a finished product.