OK - here are some odd looking things with a 6970 card and Cat 11.3 drivers. Before this I had an Nvidia GTX285 which did not have any of these aretfacts. It looks like the game does not add haze at the horizon with ATi cards.
Bright blue line on the horizon:
Distant horizon is very sharp - not blurred, even beyond the land which is correctly faded out (this is clearer at full size):
Black lines on the beach and cliffs:
