I used the NASA AIS receiver. It has worked fine and if you look at other posts here you can see some very congested screen shots of AIS data in the English Channel.
I also find that I can ‘see’ AIS transmissions of boats up to 12nm out at sea from inside the marina and inside the port of Newhaven, England.
The NASA device does look a bit cheap and one big complaint is the useless manual and the lack of any form of lights on the device to tell you it has power or is receiving or transmitting anything on the NMEA bus. Very frustrating when you are trying to troubleshoot connections. If you are particularly adept you may want to follow this advice and install your own lights.
But it does work and I have plugged it into the Brookhouse Multiplexer and from there I get two outputs. One is the NMEA 2000 (at 38,400bd) feeding into the C120 chartplotter and the other is the signal on the built in USB bus which feeds straight into a laptop without any tempremental Serial/USB converter in the way. This also means that you can reliably feed two signals into the laptop in parallel running two programs for instance without the data getting corrupted.