Right, hello chaps.
Just updated to 1.14.
In the editor I can see for absolutely miles, clean as a whistle, can stand at paraiso and see the opposite mountains across the bay, excellent.
In multiplayer the old fog is still there and I can barely see off the end of the runway. Now my teammate who also has a GTX has installed the 1.14 patch and it has removed the fog issue, he can see much better.
I have already uninstalled and re-installed arma/patches/drivers.