October marks the start of whale shark season at Mafia Island Marine Park, the best time of year to snorkel alongside juvenile whale sharks in Tanzania’s Indian Ocean waters. The season runs through to March 2027, with sightings most reliable from October to February when the animals congregate in shallow feeding waters off Mafia’s north coast.
What to Expect This Season
Marine Park rangers at Kilindoni report whale shark activity picking up this week, with juvenile individuals — typically between four and six metres — spotted near Utende Beach and around the Ras Mbisi conservation zone. Water visibility is currently 15 to 20 metres, improving as the southeast monsoon fully subsides.
Snorkel tour prices from Kilindoni jetty start at approximately USD 80 to 120 per person for a half-day trip, including the Marine Park entry fee of USD 30. Most camps and lodges on the island — Butiama Beach, Pole Pole Bungalows, and Mafia Island Lodge — arrange daily outings for guests and can book last-minute spots.
Booking and Conservation Rules
The Marine Park operates a strict no-touch, no-pursuit policy for whale sharks. Guides brief all snorkellers before water entry, and fins must be removed when within two metres of the animals. This protocol was reinforced in 2024 following observations of stress behaviour in aggregated individuals.
Accommodation on Mafia Island books quickly during the whale shark peak. Visitors flying from Dar es Salaam pay around USD 250 to 350 return with Coastal Aviation or Auric Air, with multiple daily flights during high season. A slower ferry from Nyamisati on the mainland takes four to five hours and costs around USD 20.
Combining Mafia with a Tanzania Safari
Mafia Island pairs well with a mainland safari itinerary. Many visitors combine three to four nights on the island with a Serengeti or Zanzibar extension for a 10 to 14-day trip. The island’s coral reef system is also exceptional during whale shark season — the reefs at Ras Mbisi hold some of East Africa’s highest coral cover, with hawksbill turtles, napoleon wrasse, and giant groupers common year-round.
Those planning a longer Tanzania trip should check the Serengeti National Park guide for wildlife timing alongside the marine season.