Since we're all on the topic of rivers and such ... Relatives of mine recently went on a Carnival cruise, and one of their stops was Newfoundland. Apparently -- and this is somewhat evenidenced from the photos I was shown -- during high tide a quite extensive portion of the river actually flows "upstream." It seems that the tide rises so high, it just flows backwards. From what they said, you could see the river fighting with itself, and there were all these swirlies and eddies and whatzits.