"You have to wonder where drifters like this got what was once a very expensive watch"
Same place I found an 18kt yg bangle, and 2 14kt yg rings when I was a teenager. In a park, under a picnic table buried in the sand.
The possiblilties are endless, if you think about it. I wonder if the clasp was broken or defective? I lost a good watch that way, and several bracelets.
Amazing story! Some thief was disappointed when they returned to that spot. Good for you!