Baía dos Golfinhos — Dolphin Bay — is the most distinctive of Pipa's beaches: a curve of sand backed by sheer red cliffs, with calm water and a near-guaranteed sighting of the small grey dolphins that live in the bay. The beach is only accessible at low tide on foot from Praia do Centro, or by boat at any time; check tide tables before you walk, as the cliffs leave no way back at high tide.
Boat trips from the central beach run hourly in the morning and tend to deliver the closest encounters. The water is clean, shallow, and warm; the dolphins generally tolerate quiet swimmers. Keep your distance, don't try to touch them, and the experience will keep itself worth doing.