A trip to Tumbulawa on Batudaka at around dusk is usually tied in with seeing the sea gypsy village.
Here, at around 17:30 or 18:00, dozens of hornbills glide home to sleep in the trees. The day we went there would have been close to 200 swooping over our heads to land.
Most of the village turned out too, it seemed -- to watch us! So it wasn't quiet enough to hear the whoosh of the great birds' wings, but this didn't detract from their graceful arrival. Be warned that the trip home on the boat will be in the near dark and dark; not good if you're a nervous passenger.
Given the location, this is really only practical if you are staying at Poya Lisa or Island Retreat.