›What is SeaLagom?
Maritime safety information in one place: every NAVAREA, coastal and NAVTEX warning from official sources worldwide, on a map, with tools for passage checks, ECDIS exports, ports and noon reports.
›Where do the warnings come from?
From the official sources: NAVAREA coordinators, national hydrographic offices, coast guards and NAVTEX stations. Every warning keeps its source and number, so you can always check the original.
›Can I navigate by SeaLagom?
No. SeaLagom is an aid to your watch and your passage planning. Official publications, Notices to Mariners and your ECDIS chart corrections always come first; a warning can be late, cancelled or read wrong.
›Is it free?
Reading the warnings, the map and search are free, and so is the ETA calculator. Wider exports, ECDIS formats, archives, voyage alerts and the API come with plans.
›How do I get new warnings for my area?
Open your NAVAREA or coastal region and subscribe: new warnings come by e-mail. You can also watch a voyage, use @sealagom_bot, or send alerts to Slack, Teams, Discord or a webhook from Integrations.
›How do I put the warnings on my ECDIS?
On a region page choose Export and pick your ECDIS make. The ECDIS hub explains each format and how to load it on the bridge.
›Does it work at sea without internet?
Yes: save an offline pack before you leave port. The desktop and Android apps keep their data offline too.
›Is there an app?
Yes: Android, a desktop app for Windows, Mac and Linux that installs from the browser, and a browser extension. All on the app page.
›Can I use the data in my own software?
Yes, through the API, with Python and JavaScript clients and an MCP server on GitHub.
›A warning looks wrong or out of date. What do I do?
Tell us in Ask anything with the region and number. We check it against the source and fix it.
›Can I comment anonymously?
Yes. Tick “Post anonymously” and other people see “Anonymous mariner”. Moderators can still see the account, only to stop abuse.
›How do I reach the team?
Comment here in Guides, write to @sealagom_bot, or find us on r/SeaLagom and X @sealagom. Human messages always come first.