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Advice of waypoints (AWP) and/or route plan of VTS

Introduction/Additional information: 
This IFM should be used by a VTS to advise its waypoints and/or its route plan. If the VTS uses this IFM 18 within an addressed binary message, then the waypoints and/or the route plan will be available to the addressed recipient, one ship, only. If the VTS uses this IFM 18 within a broadcast binary message, then the information will be available to all other ships in the VTS’s vicinity.

When transmitting, the VTS should include up to 12 advised waypoints and/or a route specified by a textual description, if available. If waypoints are transmitted, then a recommended turning radius may be transmitted for each waypoint.
Permitted as from: 
01/01/1998
Registrant: 
ITU-R.M.1371-1
Physical link: 
AIS
Message number (0=VDES-VDE): 
8
DAC or VPFI: 
1
FI / Message ID: 
18
State: 
in force
Number of slots (max): 
5
Last modified: 
29/01/2021 - 23:18
Details: 

 

  Number of bits  Description 
AWP  4 Number of advised waypoints (1-12);  0 = no waypoint = default; 12-15 = not used 
WP i.Lon  28 Longitude of advised waypoint i in 1/10 000 min (±180°, East = positive, West = negative). Field required if and as often as  1 ≤ i ≤ AWP, i = 1, 2, 3, ..., 12; field not required if AWP = 0 
WP i.Lat  27 Latitude of advised waypoint i in 1/10 000 min (±90°, North = positive, South = negative). Field required if and as often as 1 ≤ i ≤ AWP, i = 1, 2, 3, ..., 12; field not required if AWP = 0 
Advised turning radius i  12 Advised turning radius at advised waypoint i in metres; 0 = not available = default; 1-4 095 m. Field required if and as often as 1 ≤ i ≤ AWP, i = 1, 2, 3, ..., 12; field not required if AWP = 0 
Advised route specified by textual description  120 Description of the advised route in textual form, e.g. —west channel“; maximum 20 characters using 6-bit ASCII; @@@@@@@@@@@@@@@@@@@@ = not available (field must not be omitted) 
Spare  AWP  Bits  Spare. Not used. Should be set to zero 
  0, 8  4  
  1, 9  1  
  2, 10  6  
  3, 11  3  
  4, 12  0  
  5 5  
  6 2  
  7 7  
Number of bits  128-928  The number of bits of the IFM 17 may be calculated as follows: 124 + (AWP × 67) + spare 

 

 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