Our speaker is a real mopey guy, and can't shake his broken heart. The way he talks lets us know he's a he (In the original Spanish, the adjectives are masculine ones. For example, line 3 reads "Abandonado como los muelles en el alba." "Abandonado" ends in O, which tells us that it is describing a man who is abandoned.)
Other than that, we don't know his race, what he looks like, or even his job or social class. The poem really only lets us in on one fact about our speaker, which is really the focus of the entire poem: He's all hung up on his lost lover, and that's pretty much all he can think about. You might even say that our speaker is a bit obsessive, going back and forth about his lost love, his loneliness, and the woman who left him. Well, he goes on about that, and the sea—but of course it only reminds him of her. Bummer.