Swimming with Whale Sharks on Mafia Island: Season, Cost and What to Expect

If swimming beside the world's largest fish is on your list, Mafia Island is one of the best places on earth to do it. Unlike the busier whale shark destinations, Mafia offers a small-scale experience in wild conditions: a few boats, a handful of swimmers, and the open ocean.

When Is Whale Shark Season on Mafia Island?

Whale sharks can be seen around Mafia Island all year, but sightings are most reliable from October to March. The gathering off Kilindoni, on the island's west coast, usually peaks between November and February.

• October and November: the season begins and numbers build off Kilindoni.


• December to February: the peak. The water is warm, 27 to 30°C, and sightings are at their most reliable.


• March: the sharks begin to move on, but sightings are still common and there are fewer visitors.


• April to September: sightings are less reliable. This is the time for other things, such as humpback whales from July to September.

These are wild animals, so no trip can be guaranteed, but in peak season the chances are very good. For the rest of the year, see our month-by-month guide to Mafia Island.

What Happens on a Whale Shark Excursion

Excursions leave from Kilindoni, the island's main town, and take a morning.

• You leave early by boat, when the sea is calmest and the sharks feed near the surface.


• The crew scans the water for dorsal fins and feeding activity.


• When a shark is found, you slip into the water in a small group and snorkel alongside it.


• An encounter can last from 15 to 45 minutes, and it is common to swim with more than one shark on a trip.

Are Whale Sharks Dangerous?

No. Whale sharks are filter feeders that eat plankton and small fish, and they are harmless to swimmers. They are also enormous: adults here are commonly 6 to 10 metres long, and some are larger. Being in the water beside one is humbling.

The Rules in the Water

Whale sharks are a vulnerable species, and the guidelines on Mafia Island exist to protect them:

• Never touch a shark.


• Stay at least 3 metres from the body and 4 metres from the tail.


• No flash photography.


• No feeding, and no attempting to ride.


• No more than 10 snorkelers in the water with one shark.

Our guides follow these rules on every trip. Scuba diving with the whale sharks is not permitted where they feed, so this is a snorkeling experience.

Do I Need to Be a Strong Swimmer?

You need to be a competent swimmer. The trip is open-water snorkeling, and you may have to swim quickly to keep pace with a shark. We provide masks, snorkels and fins, and a guide is in the water with you the whole time.

What to Bring

• Reef-safe sunscreen


• A rash guard for sun protection


• An underwater camera or GoPro, with the flash off

What It Costs and How to Book

Our whale shark excursion costs $150 per person. That includes the boat, the guide, snorkeling equipment and the marine park fee, with nothing to add. In peak season, book 2 to 3 days ahead, because places fill quickly.

You can add the excursion when you book your room, or message us on WhatsApp at +255 787 579 033.

Where to Stay for Whale Sharks

The boats leave from Kilindoni, so staying in town means a short ride to the boat in the morning. Mafia Dream Hotel is in Kilindoni, with rooms from $65 a night including breakfast: see what is included, or read Kilindoni or Utende: where to stay.