Used by a station mounted on an aid-to-navigation. Note IALA A-124 P.19 for more bits than are here. Also covered in A-126 in ANNEX 1 - MESSAGE 21 in IALA Recommendation A-126 on the use of AIS in Marine Aids to Navigation Serves Ed 1.1. This has optional extensions. What is the IALA Page 7 that Mueller refered to for the RegioanlApp field? aka AtoN Not tested 272 F S 1 AS FATDMA RATDMA SOTDMA base AIS message number. Must be 21 aka 'F' 21 Indicated how many times a message has been repeated 0 default do not repeat any more 1 Unique ship identification number (MMSI) 1193046 IALA type of aid-to-navigation Page 136 of the 2001 edition of the IALA NavGuide. Items 1-15 are fixed, 16-31 are floating according to the spec, but think that fixed go from 5-19. 0 Default, Type of A to N not specified Reference point RACON Off Shore Structure Spare Light, without sectors Light, with sectors Leading Light Front Leading Light Rear Beacon, Cardinal N Beacon, Cardinal E Beacon, Cardinal S Beacon, Cardinal W Beacon, Port hand Beacon, Starbord hand Beacon, Preferred channel port hand Beacon, Preferred channel starboard hand Beacon, Isolated danger Beacon, Safe water Beacon, Special mark Cardinal Mark N Cardinal Mark E Cardinal Mark S Cardinal Mark W Port hand Mark Starbord hand Mark Preferred Channel Port hand Preferred Channel Starboard hand Isolated danger Safe water Special Mark Light Vessel/LANBY 28 Name of the aid-to-navigation @@@@@@@@@@@@@@@@@@@@ BUNCH OF ROCKS ATON@ Accuracy of positioning fixes low (greater than 10 m) high (less than 10 m) 1 Location of the AtoN FIX: break this out. 0 0 Type of electronic position fixing device 0 Undefined (default) GPS GLONASS Combined GPS/GLONASS Loran-C Chayka Integrated Navigation System surveyed not used - 8 not used - 9 not used - 10 not used - 11 not used - 12 not used - 13 not used - 14 not used - 15 2 UTC second when report was generated Positioning system is in manual mode Electronic position fixing system operates in estimated mode Positioning system is inoperative 62 True when the AtoN is off station On position Off position 0 Should be set to zero What to do about regional apps that may set this? 0 Receiver autonomous integrity monitoring flag not in use in use 0 Not Used 0