The longtail boats bobbing in Ao Lung belong to fishermen, not tour operators. You'll share this bay with perhaps a dozen other visitors, most of them Thai families who've driven down from Bangkok for the weekend. The limestone karsts that frame the northern edge cast shadows across the sand in the late afternoon, and you can hear hornbills calling from the forest canopy.
“One of the few Gulf Coast bays where you can snorkel a healthy reef directly from the beach.”
Tropical island lagoon from above
Wade in past the shallows and you'll find yourself suspended above staghorn corals where parrotfish graze and sergeant majors patrol their territories. The reef runs along the eastern curve of the bay, close enough that you won't need a boat. Visibility peaks in the dry months when the sediment settles and you can trace the patterns on butterflyfish from the surface.
A single vendor operates from a wooden shack beneath the casuarina trees, grilling squid over charcoal and serving som tam from a cooler packed with ice. She'll point you toward the trail that climbs the headland if you ask, where the view takes in the entire Chumphon coastline and the islands scattered offshore like stepping stones toward the horizon.