The Reversing Falls in Saint John actually do that - reverse, although "falls" could more accurately be described as "rapids". The Kennebecasis River empties into the Bay of Fundy at Saint John and at low tide the flow appears as in Vic's excellent pictures. At high tide, the flow actually reverses and salt water flows back up into the river basin. The reverse flow does create some rapids over the same river bed but not as pronounced as during the flow out.
Great shots Vic. Nice to see some sights that are familiar to me, having lived in the area for close to 6 years in the 2000's. The Inn at St. Andrews hosted some nice brunches for my family on several occasions. A beautiful area.