Where can I see mola mola?

Crystal Bay off Nusa Penida in Bali is the most accessible place in the world to meet one, on the cleaning station past the bay's Second Corner. It is demanding diving with serious downcurrents.

When is mola mola season?

July to October, peaking August–September, when cold upwelling along Bali's ocean-facing coast brings them up from deep water to cleaning stations around 20–30 meters.

How big do mola mola get?

Up to about 3.3 meters and 2,300 kg, which makes them the heaviest bony fish in the ocean. The animal seen in Bali is Mola alexandrini, the bumphead sunfish, rather than the true Mola mola.

Animal profile

Where to see mola mola

Mola alexandrini

A sunfish hanging almost motionless in blue water off Bali, showing its tall dorsal fin and the rudder-like clavus where a tail fin would be. — Mola Mola, photographed in Bali, Indonesia. Photo by Franck Fauvel · CC BY 2.5

The sunfish seen off Nusa Penida is Mola alexandrini, the bumphead sunfish — a huge, flattened, nearly tailless animal with a small beak-like mouth and a rudder-shaped clavus where a tail fin would be. Almost everyone calls it a mola mola, but genetic work published in 2017 established that the true ocean sunfish, Mola mola, is a separate species. It normally lives deep, diving beyond 600 meters to hunt jellyfish and salps, then rising to warm up between dives. From roughly July to October, cold upwelling along Bali's ocean-facing coast draws it up to shallow cleaning stations, where reef fish pick parasites from its skin — the brief window in which divers can meet it.

Size: Up to about 3.3 m and 2,300 kg
Diet: Mainly jellyfish and salps

Best places to see mola mola

Indonesia · Nusa Penida & Nusa Lembongan, Bali High confidence

Well documented, and reliably seen in season.

Best time: July to October, peaking August–September

How to identify a mola mola

An enormous flattened, near-circular body with no true tail — just a rudder-like clavus behind tall dorsal and anal fins.
A small, fused beak-like mouth, and in this species a distinct bump on the head that separates it from the true Mola mola.
Usually hanging motionless at an angle over a reef being cleaned, rather than swimming actively.

Meeting them responsibly

Do not chase, block or touch. These are deep-water animals and they spook off a cleaning station easily.
Approach slowly and stay low, keeping a respectful distance rather than swimming straight at it.
No flash. A startled sunfish leaves before it has been fully cleaned.

Frequently asked questions

Where can I see mola mola?: Crystal Bay off Nusa Penida in Bali is the most accessible place in the world to meet one, on the cleaning station past the bay's Second Corner. It is demanding diving with serious downcurrents.
When is mola mola season?: July to October, peaking August–September, when cold upwelling along Bali's ocean-facing coast brings them up from deep water to cleaning stations around 20–30 meters.
How big do mola mola get?: Up to about 3.3 meters and 2,300 kg, which makes them the heaviest bony fish in the ocean. The animal seen in Bali is Mola alexandrini, the bumphead sunfish, rather than the true Mola mola.