Punta Cahuita is the headland at the southern end of the national park where the coral reef lies just offshore in shallow water. The reef system here covers around 600 hectares, making it one of the larger reef formations on Costa Rica's Caribbean coast. The snorkelling is accessible without a boat — the reef begins in water shallow enough to stand in near the point — and you can reach it by walking the park trail from Kelly Creek, about 4 km from the entrance. The underwater topography includes coral heads, sea fans, and patches of seagrass that shelter juvenile fish.
The species you are likely to see include parrotfish, which crunch coral and excrete the sand you walk on; French angelfish in pairs; barracuda at the edge of visibility; and sea turtles that use the seagrass beds as feeding grounds. Nurse sharks rest on the sandy bottom between coral formations and are harmless if left alone. The best time to snorkel is in the morning before the afternoon winds pick up chop. Guided boat tours from the village can take you to sections of the reef that are not reachable on foot, including deeper formations on the outer edge.