Zanzibar Channel

The Zanzibar Channel stretches between the main island and the Tanzanian coast, sheltering some of East Africa's most diverse marine habitats. Whale sharks aggregate here from November through March, drawn by plankton blooms that also attract spinner and bottlenose dolphins in resident pods year round. The channel's shallow reefs are spectacularly healthy — a consequence of relatively low fishing pressure and strong tidal flushing — and Mnemba Atoll in the northeast corner is the crown jewel, where night dives reveal a completely different reef alive with hunting lionfish, octopuses changing colour, and sleeping parrotfish wrapped in mucus cocoons.