About seahazards

seahazards reads the official navigational-warning broadcasts (NAVAREA / HYDRO* telegrams) that national hydrographic offices publish, parses the positions and the kind of hazard out of the all-caps text, and puts them on one map with the original message and some context. It keeps every message it has ever seen, so the map can be rolled back in time.

Not for navigation

Nothing here replaces the official broadcasts. Mariners must receive navigational warnings through the GMDSS services (NAVTEX, SafetyNET / SafetyCast) as required by SOLAS and follow their national MSI service. This site can lag, mis-parse a position or mis-classify a message; the original text is always shown so you can check. Depth, wind and wave figures are model context, not measurements, and are not for navigation either.

Warning sources

• U.S. National Geospatial-Intelligence Agency (NGA) — Maritime Safety Information
  NAVAREA IV & XII, HYDROPAC, HYDROLANT, HYDROARC — live in-force lists and the 1997– archive
  Terms: U.S. Government work, public domain. NGA claims no copyright in the nautical products posted for public use.
• Japan Coast Guard, Hydrographic and Oceanographic Department (JHOD)
  NAVAREA XI (Japan, Korea, South-East Asia)
  Terms: Government of Japan Standard Terms of Use v2.0 (CC BY 4.0-compatible; commercial use permitted with attribution).
  Source: Japan Coast Guard Hydrographic and Oceanographic Department, NAVAREA XI navigational warnings — processed and re-formatted by seahazards.com (出典：海上保安庁ホームページを加工して作成).
• Instituto Hidrográfico de la Marina (Spanish Navy)
  NAVAREA III (Mediterranean and Black Sea) — in-force list
  Terms: Spanish public-sector information re-use regime (Ley 37/2007, RD 1495/2011): commercial re-use permitted with source citation; meaning must not be distorted; no endorsement implied.
  Origen de los datos: Ministerio de Defensa — Instituto Hidrográfico de la Marina (NAVAREA III).
• Australian Maritime Safety Authority (AMSA) — JRCC Australia
  NAVAREA X (Australian, Indian and Southern Ocean sectors) and AUSCOAST coastal warnings
  Terms: Creative Commons Attribution 4.0 International (amsa.gov.au/copyright); commercial re-use permitted with attribution.
  © Australian Maritime Safety Authority. Licensed under CC BY 4.0; re-formatted by seahazards.com.

NGA disclaimer (shown at NGA's request wherever its data is reproduced): “This reproduction, partial or complete, of any National Geospatial-Intelligence Agency (NGA), National Imagery and Mapping Agency (NIMA) or Defense Mapping Agency (DMA) product, information or data is not approved, authorized or endorsed by the Secretary of Defense, the Director of National Intelligence, the Director, NGA or any other element of the US Government. The US Government and NGA accept no liability for the accuracy or quality of this reproduction or the use of any NGA, NIMA or DMA products, information or data.”

Other NAVAREA coordinators are added only where their published terms allow re-use, or once written permission has been obtained. Areas not listed above are not covered yet.

Context data

• MET Norway — Locationforecast 2.0
  wind at the warning position (in-force warnings)
  Terms: CC BY 4.0 / NLOD 2.0.
  Weather data from MET Norway, licensed under CC BY 4.0.
• NOAA WaveWatch III via PacIOOS ERDDAP
  significant wave height and period
  Terms: May be used and redistributed for free; not intended for legal use.
  Wave data provided by PacIOOS (www.pacioos.org), part of the U.S. Integrated Ocean Observing System (IOOS®), funded in part by NOAA Award #NA21NOS0120091.
• HYCOM Consortium / U.S. Navy — ESPC-D-V02 global ocean analysis
  surface current and the drift hint on drifting hazards
  Terms: "DoD DISTRIBUTION A. Approved for Public Release; Distribution Unlimited"; provided as is, no warranty.
  Ocean current data: HYCOM Consortium / U.S. Naval Research Laboratory (ESPC-D-V02), via tds.hycom.org.
• GEBCO 2020 Grid via opentopodata.org
  water depth at the warning position
  Terms: Public domain; acknowledgement required; not for navigation.
  GEBCO Compilation Group (2020) GEBCO 2020 Grid (doi:10.5285/a29c5465-b138-234d-e053-6c86abc040b9), served by opentopodata.org.
• The Space Devs — Launch Library 2
  matching missile / rocket hazard areas to scheduled launches
  Terms: Free to use; attribution appreciated.
• Wikidata
  nearest volcano names for volcanic-activity warnings
  Terms: CC0.
• Natural Earth
  nearest-port and coastline data
  Terms: Public domain.
• OpenFreeMap / OpenMapTiles / OpenStreetMap contributors
  base map tiles
  Terms: Free public instance; attribution shown on the map.
  © OpenMapTiles, data from OpenStreetMap contributors (ODbL).

Linked, not reproduced: U.S. Coast Guard International Ice Patrol / U.S. National Ice Center (iceberg bulletins) · World Shipping Council — Containers Lost at Sea report · IMB Piracy Reporting Centre · ReCAAP ISC · UKMTO · MDAT-GoG · JMIC · NATO Shipping Centre (security advisories) · Smithsonian Global Volcanism Program (volcano reports). One-line plain-English summaries are generated with a large language model from the original text and are checked against the rule-based category; they can be wrong — the telegram is the record.

Contact

Corrections, take-down requests from a data publisher, or API access: see API access.