USCG Navigation Restriction Resolver

Check a point, a vessel route or a bounding box against current official U.S. Coast Guard maritime safety information. Returns one structured record listing the intersecting safety zones, hazards to navigation, marine construction, marine events, naval activity, space-operation areas, temporary aids-to-navigation changes, TESS advisories and geospatial MSIBs, with official text, validity windows, geometry and source provenance.

Not navigational advice. This Actor reports official notice records. It never says a route is safe, clear or unrestricted. Zero matches means no matching records were found in the official datasets successfully checked. It is not a statement that navigation is hazard-free or unrestricted. Mariners must still consult official charts, current Local and Broadcast Notices to Mariners, VHF broadcasts and applicable Coast Guard instructions, and follow onboard navigation and safety procedures.

What it does

Point / route / bbox → official USCG NAVCEN Maritime Safety Information layers → spatially relevant notices.

• Source: the GeoJSON layers published by the USCG Navigation Center (NAVCEN) at navcen.uscg.gov/msi. No third-party data.
• Geometry: buffers and intersections are computed in a local azimuthal-equidistant projection centred on your query, so nautical-mile radii and corridors are real distances (not degree buffers). Reported distances are geodesic on the WGS84 ellipsoid.
• Time: each notice is classified active, upcoming or unknown (no dates published) at atTime (default: now). Expired notices are excluded and counted.
• Coverage: every dataset file checked is listed with its status (success, unavailable, timeout, invalid_format, listed_but_not_published) and publication time. A failed layer makes the result partial; it never looks like zero notices.
• Listed but not published: if NAVCEN's file index lists a file that NAVCEN does not serve (HTTP 404), it is reported in coverage.unpublishedDatasets. It is not treated as checked or empty, so coverage is incomplete and coverage.coverageNote says records there were not checked.
• Per-file category coverage: coverage.categories gives each requested category a status (complete, partial, unavailable) and lists its dataset files as checked, unavailable or listedButNotPublished. A category with any file checked stays in categoriesChecked; if some of its files were not checked it is also in categoriesPartiallyChecked. Example: today NAVCEN lists safeZoneLine_1 but does not serve it, so safety_zone is partial with safeZone_1 and safeZonePoly_1 checked.

Input

Provide exactly one of point, route or bbox (WGS84 decimal degrees).

{"point": {"lat": 40.89, "lon": -73.78}, "radiusNm": 5}

{"route": [{"lat": 29.31, "lon": -94.70}, {"lat": 29.73, "lon": -95.03}], "corridorNm": 1}

{"bbox": {"south": 40.4, "west": -74.3, "north": 40.9, "east": -73.7}}

Field	Notes
point + radiusNm	Default 5 nm, 0.1–50 nm.
route + corridorNm	2–200 ordered positions you supply (≤1500 nm). Corridor half-width default 1 nm, 0.1–25 nm. The Actor does not plan routes.
bbox	≤10° per side; must not cross the antimeridian.
atTime	ISO 8601 with timezone. Default now (UTC).
categories	Optional subset of safety_zone, hazard_to_navigation, marine_construction, marine_event, naval_activity, space_operation, temporary_change, tess_advisory, msib.

Named places (e.g. "Port Canaveral") are not resolved in v1; pass coordinates.

Output (one dataset item)

Field	Meaning
status	success (all requested layers checked), partial (some layers failed), source_unavailable, invalid_input.
coverage	categories (per-category status and files), categoriesChecked, categoriesPartiallyChecked, categoriesUnavailable, categoriesFailed, categoriesIncomplete, completeForRequestedLayers, coverageNote, sourceFailures, unpublishedDatasets, per-file datasets, notCovered.
summary	matchedNoticeCount, activeCount, upcomingCount, unknownValidityCount, expiredExcludedCount, categoriesMatched, byCategory.
notices[]	category, title, validity, effectiveWindow, official GeoJSON geometry, relationshipToQuery (intersectsQueryGeometry, withinSearchArea, minimumDistanceNm, routePosition), verbatim officialText, source (dataset URL, record dates).
scopeNote	What a zero-match result does and does not mean.

Route results are ordered by routePosition (approximate fraction of your route length where the notice is nearest or first intersected); point and bbox results by distance. No severity score is invented: use the official category and wording.

Ideal use cases

Pre-voyage information gathering, maritime operations workflows, route screening, harbor/port reconnaissance, marine construction planning, space-operation awareness, and autonomous agent research.

What it does NOT do

Route planning, collision avoidance, chart replacement, navigational clearance, weather routing, legal compliance determination, or assurance of safe transit. It does not check Broadcast Notices to Mariners (planned), NOAA charts, NGA NAVAREA warnings, AIS, tides or weather.

Pricing

Pay per event: navigation-area-check $0.05 per query, plus a $0.00005 start event.

• Charged when all requested layers were checked, including zero matches.
• Charged when some layers failed but matching notices were still found (status partial).
• Not charged for invalid input, or when coverage is incomplete (failed or unpublished layers) and nothing was found.

Limitations

• Coverage is limited to what NAVCEN publishes as geospatial MSI records; notices without geometry are not returned. NAVCEN publishes dates at day granularity.
• Freshness depends on NAVCEN's publication. Layers are reused for at most a short period, and only while NAVCEN's file index shows the same publication time.
• Broadcast Notices to Mariners are not included in v1.