Maybe his owner is across the river. Maybe his owner left in a boat. Maybe the poor pup is lost and confused.
We had all sorts of hypotheses.
The dog would ignore us and just keep on barking. While I was chatting with an Austrian man who wandered up and started telling me all about his road trips in the United States in the '70s and '80s, a man came up and started throwing chunks of sand in the water. The dog stopped barking and started swimming to chase these sand chunks. Apparently the man was the dog's owner, and he said to Cheyenne: "he just likes to bark at the water."
That didn't make it in to our list of hypotheses, but you tell it little dog.