This IFM should be used by a ship to report its waypoints and/or its route plan. If the reporting ship uses this IFM 17 within an addressed binary message, then the waypoints and/or the route plan will be available to the addressed recipient, e.g. VTS or other ship, only. If the reporting ship uses this IFM 17 within a broadcast binary message, then the information will be available to all other AIS stations in its vicinity.
When transmitting a route plan the transmitting station should include up to 14 next waypoints (NWP), if available, and/or a route specified by a textual description, if available. The next waypoints should be transmitted in the order of the intended passage.
|Number of bits||Description|
|NWP||4||Number of next waypoints available (1-14); 0 = no next waypoint available = default; 15 = not used|
|WP i.Lon||28||Longitude of next waypoint i in 1/10 000 min (±180°, East = positive, West = negative). Field required if and as often as 1 ≤ i ≤ NWP, i = 1, 2, 3, ..., 14; field not required if NWP = 0|
|WP i.Lat||27||Latitude of next waypoint i in 1/10 000 min (±90°, North = positive, South = negative). Field required if and as often as 1 ≤ i ≤ NWP, i = 1, 2, 3, ..., 14; field not required if NWP = 0|
|Route specified by textual description||120||Description of the route information in textual form, e.g. —West channel“; maximum 20 characters using 6-bit ASCII; @@@@@@@@@@@@@@@@@@@@ = not available (field must not be omitted)|
|Spare||NWP||Bits||Spare. Not used. Should be set to zero|
|Number of bits||128-896||The number of bits of the IFM 17 may be calculated as follows: 124 + (NWP × 55) + spare|
The number of slots used for this message depends on the number of next waypoints transmitted as
|Number of next waypoints transmitted||0||1||2||3||4||5||6||7||8||9||10||11||12||13||14|
|Number of slots used for this message||2||2||2||3||3||3||3||4||4||4||4||5||5||5||5|