Komodo: Sangeang Volcano – Hot Rocks Dive Site – Komodo National Park

Site Overview

Sangeang Volcano Hot Rocks is a remarkable dive site on the slopes of Sangeang Api where underwater thermal vents create columns of superheated water rising from the volcanic substrate, producing one of the most otherworldly diving experiences in Indonesia. The site is named for the large volcanic boulders at 5 to 15 meters that are heated from below by volcanic activity, creating visible shimmering thermoclines and water temperatures that can reach 38 degrees Celsius near the vent openings. The volcanic slope descends from 3 meters to approximately 25 meters, with the thermal vents concentrated at 8 to 18 meters where gas bubbles rise continuously from the seafloor in mesmerizing streams. The heated rocks are covered in unique thermophilic organisms — specialized bacteria, sponges, and invertebrates that thrive in the elevated temperatures and are found nowhere else. The surrounding volcanic slope supports soft corals, crinoids, and anemones, while the black sand patches harbor extensive garden eel colonies, shrimp gobies, and colorful mantis shrimp. The mineral-rich environment supports an extraordinary diversity of nudibranchs and flatworms, making Hot Rocks a macro photography paradise. Reef fish are attracted to the warm water columns, swimming curiously through the thermal streams. Visibility can be reduced near the vents due to mineral particles, adding to the surreal atmosphere. Hot Rocks is best dived from April through December and is accessible from Labuan Bajo by speedboat, typically included on liveaboard itineraries.