AIS Message Definitions

AIS Message: timed_circular_notice (366:63:1)


Timed circular notice

Note: This message can be broadcast with a timetoexpire of 0 to indicate that a region is known to not have a currently active notice.

Note: Proposed transmission scheme for areatype=0 (right whale acoustic): A notice will be sent every 3 minutes for each buoy. Messages will be sent with timetoexpire of 0 when no acoustic detection has occured in the last 24 hours. When an acoustic detection, the system will send an separate broadcast for that buoy as soon as possible in addition to the normal 3 minute schedule.

Note: The (lat,lon,areatype) provide the key/id for each message. Any system is expected to overwrite any prior message message with a new message when it is received. This provide the mechanism to cancel out of date messages before they expire or extend the messages further into the future.

Name NumberOfBits ArrayLength Type Units Description
MessageID 6 uint AIS message number. Must be 8
RepeatIndicator 2 uint Indicated how many times a message has been repeated
0: default
3: do not repeat any more
UserID 30 uint Unique ship identification number (MMSI)
Spare 2 uint Reserved for definition by a regional authority.
dac 10 uint Designated Area Code - 366 for the United States
fid 6 uint Functional IDentifier - 63
month 4 uint Start time of most recent notice UTC month
day 5 uint Start time of most recent notice UTC day of the month 1..31
hour 5 uint Start time of most recent notice UTC hours 0..23
min 6 uint Start time of most recent notice UTC minutes
longitude 28 decimal degrees Center of the area/zone East West location
latitude 27 decimal degrees Center of the area/zone North South location
timetoexpire 15 uint Minutes Minutes from the start time until the notice expires. Max is aprox 23 days
0: No detection or notice not active in region
radius 14 udecimal m Distance from center of detection zone (lat/lon above). Distance in increments of 10 meters
areatype 8 uint What does this circular area represent
0: Right whale detection
1: Restricted Area
2: Prohibited Area (no unauthorized entry)
4: Diving operations
5: Underwater obstruction
6: Fishing nets
7: Oil in water
9: Towing prohibited
10: Anchorage area (large vessels)
11: Anchorage area (small vessels)
12: Anchorage area (general)
13: Anchorage area (deep water)
14: Anchorage area (tanker)
15: Anchorage area (24h max)
16: Anchorage area (explosives)
17: Sea-plane landing area
18: Anchorage area (sea planes)
20: Anchoring prohibited
21: Fishing prohibited
23: Actively dumping explosives
24: Actively dumping
30: Firing danger area
31: Military area, entry prohibited
32: Mine-laying practice area
33: Submarine transit and exercise area
34: Mine field
61: Fast ice
62: Sea ice
63: Logs
65: Dredging area
66: Cargo transhipment area
67: Incineration area
70: SAR - Region of search (what SAR keys should there be?)
71: SAR - Man Overboard
80: Debris, Generic
90: Restricted visibility
91: Restricted visibility, fog
92: Restricted visibility, smoke
100: Autonmous Underwater Vehicle (AUV) operations
101: Remotely Operated Vehicle (ROV) operations - teather in water
102: Diving operations
103: Swimmers in water
111: LNG security zone