Tanzania's reef island without the resorts — whale shark diving, dhow harbours, and fewer visitors than Zanzibar sees in an afternoon
Mafia Island lies 120km south of Dar es Salaam in the Mafia Channel, between the Tanzanian mainland and the open Indian Ocean — an island of mangrove creeks, coral reef, and ruined Shirazi settlements that receives a fraction of Zanzibar's visitors while offering diving that many rate higher. The Mafia Island Marine Park covers 822km² of reef and sea grass, protecting the largest aggregation of whale sharks in East Africa (present from October to March as they feed on spawning fish above the Kilindoni reef platform). Chole Island, in Chole Bay off Mafia's eastern coast, has the ruins of an 18…
Mafia Island was a significant node in the pre-Portuguese Indian Ocean trade network — archaeological evidence shows settlement from at least the 9th century CE, with the Shirazi culture (Swahili-Persian trading civilisation) establishing towns on Chole and Juani islands. Arab and Persian merchants from the Gulf used Chole Bay as a staging point for monsoon crossings. Mafia came under the Sultanate of Zanzibar's influence in the 19th century, then briefly under German East Africa administration from 1890. It was traded to Britain in the 1890 Heligoland-Zanzibar Treaty — one of the more remark…