Dive Site: Nusa Penida, Indonesia

Home to one of the most frequently visited sunfish cleaning stations in Nusa Penida, in season it’s not unusual to see several of these giants on a single dive.

Bali in Indonesia is a favorite destination for tourists from all over the world for many reasons. Some come to relax on tranquil beaches beneath the shadow of great volcanoes. Others come to see to the temples and teeming markets that constitute Balinese culture, or to sample Indonesian cuisine. For divers, Bali is known as the location of one of Southeast Asia’s most famous wrecks, the SS Liberty in Tulamben. The island is also ideally situated as a jumping-off point for the more remote dive destinations scattered like so many jewels to the east of the archipelago. In their haste to reach places like Komodo, Lembeh and Raja Ampat, however, many divers miss out on one of Bali’s best-kept secrets, the annual appearance of one of the ocean’s most elusive creatures, the ocean sunfish or mola mola, at the dive sites of nearby Nusa Penida. Boasting spectacular diving of its own, Nusa Penida lies in Badung Strait between Bali and Lombok and is most easily accessible via the Balinese town of Sanur. Along with its two sister islands, Nusa Lembongan and Nusa Ceningan, this little-known gem is one of the best places in the world to get up close and personal with a mola mola. Weighing in at over 2,200 pounds (1,000 kg) and reaching lengths of up to 10 feet (3 meters), the sunfish is the world’s largest bony fish, and with its disc-shaped body and long dorsal and anal fins it is also one of the strangest.

Adult sunfish spend the majority of their lives at depths of over 655 feet (200 meters), only occasionally coming into shallower water to visit cleaning stations. These behavioral patterns explain why Nusa Penida and its sister islands are one of the few places on Earth where divers can reliably see these strange creatures. Deep-water trenches, with a chasm over 820 feet (250 meters) deep, separate Nusa Penida and Nusa Ceningan, while the walls on the northern side of Nusa Penida plummet into an abyss some 1,970 feet deep (600 meters). Upwellings of cool, nutrient-rich water are channeled through these trenches, combining with the deep water to provide perfect conditions for the islands’ sunfish. Although these ocean giants can be seen throughout the year, July through October offers the most reliable chances for sunfish sightings. There are three Nusa Penida sites that the fish seem to favor: Blue Corner, Toyapakeh and most famously, Crystal Bay. There, established sunfish cleaning stations allow divers to witness these amazing animals up close, as they allow shoals of colorful threadfin bannerfish and cleaner wrasse to attend to their grooming needs. Ocean sunfish can carry as many as 40 different species of parasite on their skin, and rely on their visits to the cleaning stations to provide much-needed relief.

At the Crystal Bay dive site, the sunlit shallows of the bay itself are a colorful wonderland of vibrant corals. At the mouth of the bay, the reef slopes downwards into the cool blue of the deep-water trench, where, away from the protection of the bay, the current is often strong and can be unpredictable. Due to the combination of current and depth, the Crystal Bay wall is only appropriate for experienced divers, but if you can cope with the sometimes-challenging conditions, this dive could be one you will never forget. It’s home to one of the most frequently visited sunfish cleaning stations in Nusa Penida, and in season it’s not unusual to see several of these giants on a single dive. The visibility is typically excellent, and yet the sunfish’s mottled silver and grey skin is surprisingly well camouflaged against the clear blue of the ocean. They hang motionless above the cleaning stations, in apparent ecstasy, as darting cleaner wrasse rid them of their unwanted lodgers, their huge size making them seem strangely out of proportion. They are like nothing else in the sea, with their large round eyes and comically small pectoral fins. And yet, despite their odd appearance, the sunfish possess a kind of magic that holds you in thrall while they’re present. They are beautiful, in their own unique way, and to see them in their natural environment is a privilege that few people have.

As the current sweeps you onward past the cleaning stations, keep an eye on the blue, where sunfish are often seen on their way to or from the reef. In the open ocean, their elongated dorsal and anal fins undulate in lazy synchronicity, directing the course of their enormous bodies. When seen from below, the sunfish become magnificent silhouettes against the blue prism of sunlight filtering from the surface. The dive sites of Nusa Penida are home to several other fascinating species, to, including turtles, reef sharks and huge manta rays. Mantas can be seen at dive sites such as the predictably named Manta Point throughout the year, where the giant rays also take advantage of the cleaning services that bring in the sunfish. Although Nusa Penida is far less well known than other Indonesian dive sites to the east, it can nevertheless become busy during sunfish season. For the best experience possible, choose a dive center that limits its dive group size and screens divers to ensure that they are capable of coping with the challenging conditions of dive sites like Crystal Bay. Because sunfish can be shy and are often scared away if they feel threatened, it is also important to maintain a respectful distance during encounters; that way, you’ll maximize your time with these ocean giants and make sure the experience is a positive one for divers and sunfish alike.