It is annoying that the Raymarine C and E series which have an AIS interface have no displays to show whether AIS is actually working but has no data to display.
Both these displays simply say “No AIS” in the top right hand status corners of the screen. From the software developers point of view they probably would say indignantly that this language is consistent with the message displayed before the GPS Fix is obtained – in other words “No Fix”.
But the difference is this:
1. “No Fix” means the GPS is still obtaining satellite and the chartplotter is calculating the position of the boat. After few minutes if no fix is still displayed you know the GPS is not working and you need to fault trace. So the passage of time adds another piece of vital data that helps you decide that something is wrong (assuming the USA has not declared war and switched off the whole GPS system!)…whereas…
2. “No AIS” means two different things –
a. the AIS is fully functional, is receiving transmissions, but there are none to display, or
b. the AIS is NOT fully functional, is NOT receiving transmissions, and you need to due some fault tracing…straight away
This means you can set sail unaware that the AIS is faulty – but you would be totally aware if the GPS was faulty.
Please Raymarine, do something about AIS error detection – a suitable button could live nicely on the MARPA/AIS settings toolbar.