Ha, yes that was just talking about C1 sets.
I personally haven't stumbled across as much variation in C2 but I don't know. I am happy to be enlightened; for me that is what these discussions are about. As far as I have seen, there are:
C2 River I (no watermark, base)
C2 River I (watermark, BB6)
C2 River II (watermark, expansion 6)
C2 River20?
I am still waiting for my Z-man Anniversary edition to exist; May, became July, became September... we shall see. HiG should make an expansion that includes a flying pig.