AIS Maritime schema

The AIS Maritime dataset contains ~1.4M normalized vessel positions sourced from terrestrial and satellite AIS receivers, enriched with vessel identity from IMO registries, behavior anomaly detection, and linkage to Codex port events. Records are ingested continuously and published as monthly immutable snapshots. Every record inherits the full APRS envelope (record_id, chunk_id, bitemporal fields, confidence_score, provenance) and carries the join keys documented below.

Dataset-specific fields

Vessel identity

Field	Type	Nullable	Description
`imo`	integer	yes	IMO number (7-digit). Primary vessel identifier per IMO A.600(15).
`mmsi`	string	yes	Maritime Mobile Service Identity (9-digit). Fallback identifier.
`vessel_name`	string	yes	Vessel name (max 20 ASCII characters per AIS message 5).
`call_sign`	string	yes	Radio call sign (max 7 characters).
`flag_state`	string	yes	ISO 3166-1 alpha-3 country code.
`vessel_type`	string	yes	Codex 6-category enum: `container`, `tanker_crude`, `tanker_product`, `bulker`, `fishing`, `other`. Raw ITU code preserved in metadata.
`dwt`	numeric	yes	Deadweight tonnage in metric tonnes.
`length_oa`	numeric	yes	Length overall in meters.
`beam`	numeric	yes	Beam in meters.
`draught`	numeric	yes	Draught in meters.

Position and kinematics

Field	Type	Nullable	Description
`lat`	float	no	WGS84 latitude.
`lng`	float	no	WGS84 longitude.
`speed`	float	yes	Speed over ground in knots (0.1 kn resolution).
`course`	float	yes	Course over ground in degrees (0.1° resolution).
`heading`	float	yes	True heading in degrees (1° resolution).
`nav_status`	string	yes	AIS navigation status (0–15). Codex emits both the numeric code and a human-readable label.
`rot`	float	yes	Rate of turn in degrees per minute (decoded from AIS-coded ±127 value).
`timestamp`	timestamptz	no	UTC timestamp of the position fix.
`h3_index`	string	no	H3 resolution-8 cell derived from `lat`/`lng`.

Codex enrichments

Field	Type	Nullable	Description
`behavior_anomaly_flag`	boolean	no	`true` when kinematic or behavioral anomaly detected (AIS gap, speed anomaly, or route deviation).
`port_event_id`	UUID	yes	Links to the corresponding event in Events Timeline when the position falls inside a port polygon.
`beneficial_owner_urn`	string	yes	Entity resolution link to the vessel’s beneficial owner.
`sanctioned_owner`	boolean	yes	`true` when the beneficial owner appears on a sanctions list.

Vessel types

The raw ITU vessel type code (0–99) is preserved in metadata.itu_vessel_type_code. Codex normalizes vessels into six categories for consistent filtering:

Category	Description
`container`	Container ships
`tanker_crude`	Crude oil tankers
`tanker_product`	Product and chemical tankers
`bulker`	Dry bulk carriers
`fishing`	Fishing vessels
`other`	All other vessel types

Code	Label
0	Under way using engine
1	At anchor
2	Not under command
3	Restricted maneuverability
4	Constrained by draught
5	Moored
7	Engaged in fishing
8	Under way sailing

AIS positions in the Codex dataset are compressed to one per minute per vessel. In Overwatch, live positions are kept at full resolution for 7 days and then downsampled through progressive tiers. Both raw and compressed views are available depending on your tier.

Join keys

Key	Presence	Notes
`record_id`	always	APRS URN
`chunk_id`	always	Deterministic from `record_id`
`imo`	often	Primary vessel identity. Null for small craft without IMO numbers
`mmsi`	always	Fallback vessel identity
`h3_index`	always	H3 resolution-8 spatial key
`port_event_id`	sometimes	Links to Events Timeline for in-port positions
`beneficial_owner_urn`	sometimes	Entity resolution link to beneficial owner

Example query

Find vessels flagged as anomalous near a specific port in the last 30 days:

SELECT
  record_id,
  vessel_name,
  imo,
  mmsi,
  timestamp,
  speed,
  nav_status,
  behavior_anomaly_flag,
  sanctioned_owner
FROM read_parquet('ais-maritime-2026-04.parquet')
WHERE h3_index = '88283082b9fffff'
  AND behavior_anomaly_flag = true
  AND timestamp >= now() - interval '30 days'
ORDER BY timestamp DESC;

Known limitations

imo is null for small craft, fishing vessels, and some flag-of-convenience registrations. Use mmsi as a fallback.
vessel_type normalization collapses 99 ITU codes into 6 categories — check metadata.itu_vessel_type_code when you need the original classification.
beneficial_owner_urn is populated by the entity resolution pipeline and may be null for recently ingested positions.
Position compression (1-per-minute) means sub-minute maneuvers are not visible in the default view.

Get started

Frameworks

Reference

Dataset-specific fields

Vessel identity

Position and kinematics

Codex enrichments

Vessel types

Navigation status codes

Join keys

Example query

Known limitations

​Dataset-specific fields

​Vessel identity

​Position and kinematics

​Codex enrichments

​Vessel types

​Navigation status codes

​Join keys

​Example query

​Known limitations

Dataset-specific fields

Vessel identity

Position and kinematics

Codex enrichments

Vessel types

Navigation status codes

Join keys

Example query

Known limitations