AIS Navigation Status Codes

Understanding the 16 navigation status codes transmitted by vessels via AIS to indicate their current operational state.

16 Status Codes4-bit Value (0-15)Manually Set by Crew

Complete Navigation Status Reference

All 16 possible navigation status values as defined in the ITU-R M.1371 standard. These codes are transmitted in AIS messages 1, 2, and 3.

CodeStatusDescription
0Under way using engineVessel is moving under its own power
1At anchorVessel is anchored and stationary
2Not under commandVessel unable to maneuver as required by rules
3Restricted manoeuvrabilityVessel limited in ability to maneuver due to work
4Constrained by her draughtVessel limited by water depth relative to draught
5MooredVessel secured to a fixed structure or dock
6AgroundVessel has run aground
7Engaged in FishingVessel actively fishing (not transiting)
8Under way sailingVessel moving under sail only
9Reserved for future amendmentHSC (High-Speed Craft) in some implementations
10Reserved for future amendmentWIG (Wing-In-Ground) in some implementations
11Power-driven vessel towing asternVessel towing another vessel or object
12Power-driven vessel pushing ahead or towing alongsideVessel pushing or towing alongside
13Reserved for future useNot currently assigned
14AIS-SART (active)Search and Rescue Transponder is active
15UndefinedDefault value, status not set

Most Common Navigation Statuses

In practice, you'll encounter these five statuses most frequently in AIS data.

0

Under way using engine

~60%

of all AIS data

5

Moored

~25%

of all AIS data

1

At anchor

~8%

of all AIS data

7

Engaged in Fishing

~3%

of all AIS data

15

Undefined

~2%

of all AIS data

Important: Navigation Status Reliability

Navigation status is manually set by the vessel's crew and is often not updated correctly. Common issues include:

  • Vessels showing "Under way" while actually moored
  • Fishing vessels not updating to "Engaged in Fishing"
  • Default value (15) left unchanged

Best practice: Combine navigation status with speed, heading changes, and position patterns for more accurate vessel state determination.

Using Navigation Status in Applications

How different industries leverage navigation status data for operational insights.

Port Operations

Track vessels transitioning between moored, at anchor, and under way states

Moored (5)At anchor (1)Under way (0)

Fishing Monitoring

Identify vessels actively fishing vs transiting between fishing grounds

Engaged in Fishing (7)Under way (0/8)

Safety Alerts

Monitor for emergency conditions requiring attention

Not under command (2)Aground (6)AIS-SART (14)

Traffic Analysis

Understand vessel movement patterns and congestion

Under way (0)Restricted (3)Constrained (4)

Navigation Status in API Response

The navstat field in our API returns the numeric navigation status code.

{
  "mmsi": "211234567",
  "name": "ATLANTIC STAR",
  "navstat": 0,
  "navstat_text": "Under way using engine",
  "speed": 12.4,
  "course": 245.5,
  "heading": 244,
  "lat": 51.8892,
  "lon": 4.3456,
  "timestamp": "2024-01-15T14:32:18Z"
}

Our API provides both the numeric code (navstat) and human-readable text (navstat_text) for convenience.

Query Vessels by Navigation Status with Our API

Now you can programmatically find all vessels matching a specific navigation status using our Vessels by Navigation Status API. Filter by status, world zone, vessel type, and laden condition to identify vessels that meet your exact criteria.

POST Request ExampleJSON Body
POST https://datadocked.com/api/vessels_operations/get-vessels-by-navigational-status
Headers:
  x-api-key: YOUR_API_KEY
  Content-Type: application/json

Body:
{
  "navigational_status": "at-anchor",
  "world_zone": "baltic-sea",
  "vessel_type": "bulk-carrier",
  "laden": "ballast"
}

Response:
{
  "vessels": [
    {
      "imo": "9876543",
      "mmsi": "123456789",
      "name": "VESSEL NAME",
      "country": "Panama",
      "shipType": "Bulk Carrier"
    }
  ]
}

Use Cases

  • • Find vessels at anchor in specific regions
  • • Identify available tonnage for cargo bookings
  • • Monitor fleet operational status
  • • Track vessels by laden/ballast condition

Navigation Status Values

  • under-way - Vessel underway using engine
  • at-anchor - Vessel at anchor
  • moored - Vessel moored
  • drifting - Vessel drifting (no zone needed)

Access Real-Time Navigation Status Data

Get live vessel positions with navigation status updates through our API. Start with 100 free credits.