The Waterways Management message can be used to facilitate vessel traffic movement in confined waters. More “directive” than advisory, this message can be broadcast (e.g., information for all ships or a group of ships) or addressed (e.g., information/direction to a single ship). Examples include: lock, gate, narrows, or single passage area.
There are two sub-types of this message; 1) for providing a position/name of the waterway feature, and 2) for providing a list of vessels and their sequence order/times. Specific information for each vessel includes: sequence time, direction, and vessel MMSI. The complete list of message types is contained in Table 5.
Usage Notes
Portrayed as a text list linked to geographic location on the chart.
Dr. Gregory Johnson, gwjohnson@alionscience.com(link sends e-mail)
Parameter | # of Bits | Description | ||
---|---|---|---|---|
Standard Message Header | Message ID | 6 | Identifier for Message 8; always 8. | |
Repeat Indicator | 2 | Used by the repeater to indicate how many times a message has been repeated. 0 – 3; 0 = default; 3 = do not repeat any more. Set to 0 (default). | ||
Source MMSI | 30 | MMSI number of source station. This varies according to the transmitter ID. | ||
Spare | 2 | Not used. Set to zero. | ||
Binary Data | Designated Area Code | 10 | Designated area code (DAC). This code is based on the maritime identification digits (MID). (See Rec. ITU-R M.1371-3 § 2.1, Annex 5). Set to 366 (US). | |
Function Identifier | 6 | Function identifier. The meaning should be determined by the authority that is responsible for the area given in the designated area code. Set to 35. | ||
Application Data | Message Linkage ID | 10 | Identifier for the Waterways Management event. This number uniquely identifies an event and is used to connect additional information with the event. Source MMSI and this ID uniquely identify the event.Set to 0-1023 by message originator. | |
WM Type | 4 | Waterways Management Type as per Table 5.Set to 0-15 according to type. | ||
Subtype | 2 | Message subtype.0 = Sequence; 1 = Name/Position; 2-3 = (reserved for future use).Set to 0 – Sequence. | ||
Vessel 1 | 56 | First vessel. Structured as in Table 6. | ||
Vessel 2 | 56 | Optional second vessel. Structured as in Table 6. | ||
Vessel 3 | 56 | Optional third vessel. Structured as in Table 6. | ||
Vessel 4 | 56 | Optional fourth vessel. Structured as in Table 6. | ||
Vessel 5 | 56 | Optional fifth vessel. Structured as in Table 6. | ||
Vessel 6 | 56 | Optional sixth vessel. Structured as in Table 6. | ||
Vessel 7 | 56 | Optional seventh vessel. Structured as in Table 6. | ||
Total bits | 128 – 520 | 1-3 Slot Binary Message |