How Seadar works
Seadar is a free maritime registry that turns public data into complete, server-rendered vessel, port, flag-state and company pages. This page explains where every figure comes from, how we compute the statistics we publish, how we use automation, and how you can verify any number against its original source. Our aim is simple: be the page that actually answers your question, with its sources in plain sight.
Where the data comes from
Seadar combines several public datasets. Each page names the specific source behind its numbers; the full list is below.
- AIS (Automatic Identification System)Public radio broadcast
- Live position, course, speed, heading, navigational status and reported destination, broadcast by vessels and received over public AIS feeds and the Seadar receiver network.
- NOAA NDBC & CO-OPSU.S. public domain
- Marine conditions near ports — wind, waves, water and air temperature from weather buoys and tide gauges.
- USCG PSIXU.S. public domain
- Port State Control / Coast Guard inspection records: inspections, detentions and deficiencies recorded in U.S. waters.
- EU MRV / EMSA THETIS-MRVEuropean Commission open data
- Independently verified annual CO₂ and fuel figures for ships over 5,000 GT calling at EU/EEA ports (EU Regulation 2015/757).
- OFAC SDN listU.S. public domain
- U.S. Treasury Specially Designated Nationals list, matched to vessels to flag sanctions exposure.
- Wikidata & WikipediaCC0 / CC BY-SA
- Vessel and shipwreck particulars and narrative history, used to enrich identity records.
How we compute statistics
- Fleet and registry stats(fleet size, average age, gross tonnage, detention rate) are computed directly from Seadar's own records — never estimated or invented. A detention rate is detentions ÷ recorded inspections for that registry; where there are no inspections on record, we say so rather than show a zero.
- Coverage is honest. Counts reflect what Seadar has ingested, not the entire world fleet. As AIS coverage and the receiver network grow, the numbers grow with them.
- No keyword or number dumps. Tabular data is always wrapped in plain-language interpretation and a clear use case — a vessel page tells you what its safety record means, not just a wall of figures.
Automation & how pages are made
Seadar's pages are generated programmatically from structured data, with the prose templated and filled from each entity's own facts. We publish a page only when it carries a genuinely unique data point; thin records (a bare name with no particulars, position or history) are kept live but marked noindex and held out of the sitemap until they earn real data. Every page is built to help the person who landed on it, not to manipulate ranking.
Freshness
Live positions update as AIS messages arrive. Vessel, port and registry pages are cached and revalidated on a schedule (typically 15–60 minutes) so the server-rendered facts stay current without re-querying on every request. Where a page shows a "last detected" or "updated" time, that timestamp is the real recency of the underlying data.
Verifying & correcting data
Sanctions and inspection findings are serious; always confirm a match against the cited primary source — the OFAC Sanctions Search for sanctions, USCG PSIX for inspections, and EMSA THETIS-MRV for emissions. If you spot an error, you can help improve coverage and accuracy by hosting a receiver or getting in touch.
Published by Seadar. Data from AIS, NOAA, USCG PSIX, EMSA, OFAC, Wikidata and other public sources, attributed on each page.