On a visit to Plum Creek Park I saw movement of a Great Blue Heron heading for the North shore. He was in as deep as I have ever seen a heron fish.His movement then switched to the South shore. It did become a little shallower.
Finally it was able to walk comfortably as its strides moved the water.
It was very careful to pay attention but found no fish.
It stopped its movement right before the line in the water but still no fish.
I then decided to leave him as he moved away to the South shore to fish. Click on the photo if you can't see him. This was the distance I was shooting him.
There are a lot of neat critters on the above site.