Have you ever seen someone so attractive that you have to do a double-take? It's a first for Gaeta, but he definitely gives Jack a second look when he sees him strolling by the sea. And a third look. Before he can be accused of staring (fourth looks are definitely edging into staring territory), he goes over to introduce himself. It's an uncharacteristically bold move, but why not walk right on up to gorgeous strangers, right?
"Hello." A wave. Not a terribly confident wave. "We haven't met before, have we?"