In a busy harbor, you will be at full alert, and whether your AIS B is getting out or not, it gives you the location of all the big ships. I had over 130 targets listed yesterday coming across New York
Harbor, and I just figured it was up to me to get out of their way. In fog
, however, it would be nice to show up on the big ships AIS...
Some of the Class A units can't decode the static info from Class B units, so you only show up with your MMSI number, position, SOG, and COG. This happened in the Pink Lady tests, and happened to me with an aircraft carrier outside Norfolk. Its better than nothing, and get their attention. On the Pink Lady tests where the Class B didn't show up at all, I suspect they were run at the dock
, where the Class B only transmits every 3 minutes, vs every 30 seconds underway.
The Class B units aren't perfect, (in addition to the problems of being seen, there is no way to change your status, so you remain a 'sailing vessel' even when you are under power), but for $500 and a low current
drain, they are worth it to me, especially at sea, where I have had several ships alter course to miss me at about 5 miles.