Photographer Giles Davies saw the swan among a group of white ones on the Milford Haven waterway, on Saturday.
He studied the swan for some time and it is "in good condition" and "living quite happily" among the other swans.
"As for where it's come from, not a clue. I don't know," he added.
In Dawlish, Devon, the bird has become a symbol of the town
It's only 103 miles away is it one from here ???