OK:

I can confirm that the SR261 works with ShipPlotter. What are other
people using.

Most of you probably already know this but ShipPlotter can process two
types of AIS data:

via the serial port from AIS receivers/transceivers eg SR261 or

via the soundcard from a suitable VHF receiver. I use a Yaesu FT-857.
A six pin miniDIN plug goes into the rear Data socket and I set the
mode to FM or 9600packet unsquelched