Between 2012 and 2022, researchers identified 222 different whale sharks in Kilindoni Bay, on the west coast of Mafia. Nearly nine out of ten were males. This figure comes from the scientific report of the area (ISRA, 2023).
The previous version of this page promised water at 26 °C all year round, an “unpolluted” island, and whale sharks from October to March, without any source. We have completely revised it.
Here you will find the checklist we apply to each destination (level, current, season, supervision, fallback plan), then what needs to be arranged before departure in 2026: visa, mandatory insurance, and evacuation.
What does the Mafia Island Marine Park protect?
The Mafia Island Marine Park was established in 1995. It covers about 822 km², more than three-quarters of which are below the high tide line, to the south and east of the island. Diving is mainly done in Chole Bay and on the outer reefs at the bay’s exit, with reefs, seagrass beds, and mangroves within the same perimeter.
A Tanzanian tourism portal mentions about fifty types of corals and approximately 400 fish species. Take these figures as an order of magnitude. It is an inventory.
The park has an entrance fee, and this is where the old pages are mistaken.
In May 2019, the newspaper The Citizen cited an entrance fee of 24 dollars and announced a revision of the rates by the government. Since then, no official dated fee schedule has been found online. The 2026 amount therefore remains impossible to determine from here. Ask the center or lodge if the fee is included, whether it is per day or per stay, and how it is paid. Often, this kind of charge is what causes a diving budget to spiral over a full week, when no one mentioned it at the time of booking.
What level is required to dive at Chole Bay and Kinasi Pass?
Chole Bay is a sheltered bay, and operators present it as a place for beginners and introductory dives. Kinasi Pass, the channel that connects the bay to the ocean, changes completely depending on the tide time and wind strength, within a few hours. Centers describe it as a current dive, to be reserved for divers who master their buoyancy.
What level? The answer depends on the tide time, the wind, and the site chosen that morning, and no web page can give it to you personally. Your certification sets a framework. It does not say whether this pass, with this coefficient and this swell, suits your condition that day. Only the instructor decides.
The current decides more than the photo.
But visibility does not guarantee safety. Clear water in the pass can hide an outgoing current that pushes the group away from the boat, especially when the tide is ebbing and the wind strengthens, and it is precisely then that a safety sausage is useful. This is a question to ask while still on the boat. Also ask how the guide follows the bubbles.
| Criterion | Chole Bay | Kinasi Pass and outer reefs |
|---|---|---|
| Level | Supervised beginner, introductory dive, snorkeling | Certified diver comfortable with drift diving |
| Current | Generally weak, to be confirmed at briefing | Tide-related, sometimes strong |
| Supervision | Instructor, small group | Guide, boat following the group |
| Fallback plan | More sheltered site within the bay | Return to the bay if the pass is not diveable |
When to go between kaskazi and kusi?
The Tanzanian coast follows the rhythm of two monsoons. The kaskazi, from the northeast, blows roughly from November to February with lighter winds. The kusi, from the southeast, dominates from April to September with stronger winds, June and July being the windiest months. The interseasons are generally the calmest.
These ranges come from a synthesis on the Tanzanian coasts published by the ODINAFRICA network, a project of the UNESCO Intergovernmental Oceanographic Commission. They describe a general trend.
Add the rain. A Tanzanian tourism portal advises avoiding March to May (heavy rains) and November to December (light rains), and places the best visibility from October to February. But some operator pages announce “up to 30 meters” visibility in the bay, without date or measurement. Remember the period. Forget the figure.
In short, the window from October to February ticks the most boxes.
However, the kusi does not prohibit diving; it mainly reduces outings on the outer reefs when the sea gets rough, and it can block a short stay on sheltered sites for several consecutive days. If you go from June to September, plan for some buffer days. Keep a plan B in the bay.
Whale Sharks of Kilindoni: What Does Research Say?
The most solid study dates back to 2020. Christoph Rohner and his colleagues tracked 51 whale sharks using acoustic telemetry for five years in Kilindoni Bay. The animals stay in the area all year round, but they are truly visible near the coast only from October to February, when they feed on small shrimp.
The rest of the year, they stay further offshore, in deeper waters.
The tracked sharks measured from 4 to 9 meters, with a median of 6 meters, and 41 out of 51 were males. Their central zone does not exceed about 13 km². Thus, resident animals concentrate in a tiny space, which is also frequented by fishing and excursion boats. Researchers noted scars caused by propellers and nets. The species is classified as endangered by the IUCN. You will find more biological context in our article on the whale shark and its lifestyle.
No outing guarantees an encounter. A favorable season remains a probability, and an honest operator will tell you this before taking your money. The encounter usually happens by snorkeling, from a boat that spots the animals at the surface, and it is the behavior of the passengers that most affects the animal. In 2025, WWF indicated it was working with the WATONET operator network on a code of conduct for swimming. Ask the boat if it applies it. How many swimmers does it put in the water at the same time, and at what distance? And do not touch, as explained in why you should never touch marine life.
Visa, Insurance, Chamber: What Backup Plan Before Leaving?
For a French citizen, the tourist visa is requested online, only on the Tanzanian immigration service portal (immigration.go.tz). France Diplomatie specifies that the embassy in Paris has not issued visas since November 2019. The tourist visa is listed at 50 dollars, and beware of intermediary sites that charge more for the same document while presenting themselves as official.
New in 2026, verify before buying your ticket.
According to the Spanish Ministry of Foreign Affairs fact sheet updated on September 30, 2026, mainland Tanzania has required since October 1, 2026, an entry travel insurance costing 44 dollars. Mafia depends on the mainland part (Pwani region). Zanzibar, on the other hand, has imposed its own mandatory insurance since October 2024, sold by the archipelago’s public company. If your trip passes through both, you might pay twice. However, we have not found the complete official text, so reread the Tanzania fact sheet from France Diplomatie just before leaving.
Regarding safety, the same fact sheet advises great caution in the southeast of the country, near the Mozambique border. Mafia is located further north, facing the Rufiji delta. Malaria is present throughout the country, and this issue should be addressed with a doctor before departure.
Then there is the chamber. A hyperbaric medicine center was announced in January 2024 at the Muhimbili National Hospital in Dar es Salaam by Dartmouth University, which supported the project, and it primarily targets wound treatment. Its capacity to handle a decompression accident, day or night, remains impossible to determine at this time. For Zanzibar, we found no recent source. So ask the dive center for its written evacuation plan, the emergency number it calls, and the actual duration of the transfer by light aircraft. Good dive insurance covers medical evacuation. It costs less than a medical flight paid out of pocket.
If you compare with the Sainte-Anne Marine Park in the Seychelles or with Sipadan in Malaysia, keep the same criteria. For Mafia, the choice boils down to this: go from October to February, pay the high season price, plan two buffer days for the weather, and have insurance that repatriates. Would you book it this way?
FAQ
Can you dive in Mafia as a beginner?
Yes, the centers offer introductory dives and training, usually in Chole Bay, which is more sheltered. Dives in the Kinasi pass depend on the tide and current. The instructor decides on site, during the briefing.
What is the best season to see whale sharks in Mafia?
According to the study by Rohner and colleagues (2020), whale sharks are mostly visible near Kilindoni from October to February. They remain in the region the rest of the year, but further offshore. No outing guarantees an encounter.
How much does the entrance to the Mafia marine park cost?
In 2019, the Tanzanian press cited 24 dollars and announced a revision. No official fee schedule dated for 2026 was found. Ask the exact amount and payment method at the center or lodge before booking.
Is insurance required to enter Tanzania in 2026?
According to the Spanish Ministry of Foreign Affairs (updated September 30, 2026), an entry insurance costing 44 dollars has been mandatory for mainland Tanzania since October 1, 2026. Zanzibar requires its own insurance. Check on France Diplomatie before leaving.
Sources
- No Place Like Home? High Residency and Predictable Seasonal Movement of Whale Sharks Off Tanzania (Rohner et al., Frontiers in Marine Science, 2020)
- Travel Advice: Tanzania (France Diplomatie, Ministry of Europe and Foreign Affairs, consulted October 3, 2026)
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