The top attraction in Porto de Galinhas are the natural pools in the reef. It is, for sure an interesting trip, but not a good idea to have a bath.
The "pool" is small, with a crowd in it, lots of fish, and food, and... some dirt.
The best is the fun with the fish around you, and the silhouettes of the several "jangadas" circling it. It is a short ride, cheap and quick, but the same program in Maragogi is more impressive.