A quick boat hop from Stone Town leads to Prison (Changuu) Island—an 800×250 m coral islet with giant tortoises, ruined quarantine buildings and shallow snorkeling along fringing reefs. This three-hour excursion pairs short swims with a compact wildlife and history loop.
More ways to explore the area's outdoor wonders
A short boat ride cuts through the harbor and the city’s heat gives way to salt air and the clack of oars against timber. Prison Island’s low reef appears on the horizon—an 800 m by 250 m coral outcrop crowned with scruffy casuarina and the stone remains of a never-used prison block. Shorebreak and gulls announce the island before your boots hit sand.
Difficulty
easy
Duration
3 hours
Fitness Level
Light activity; suitable for most fitness levels with short swims and low-impact walking on uneven paths.
Wildlife
History
Changuu was developed in the late 19th and early 20th centuries as a quarantine and prison project; its tortoise population began with Seychelles donations in 1919.
Conservation
Stick to marked paths, use reef-safe sunscreen, and avoid touching coral—small choices reduce long-term impacts on fragile reef and island habitats.
Reserve your spot on the Prison Island (Quarantine Island) Tour and Snorkeling Activities in Zanzibar today and enjoy a trusted, highly rated experience designed to help you make the most of your adventure.
Use reef-safe sunscreen
Protect coral and avoid fines—choose a biodegradable, reef-safe sunscreen and apply before you board.
Wear water shoes
Entries can be rocky; lightweight water shoes protect feet when stepping off the skiff and walking shorelines.
Go early for calmer seas
Morning crossings usually offer better visibility and gentler water for snorkeling; afternoons can be choppier with onshore wind.
Respect the tortoises
Observe the Aldabra tortoises from the path—do not feed or climb fences and follow guide instructions to minimize stress on animals.
Snorkel mask & snorkel
Provided in many tours but bring your own for fit—improves visibility and comfort in the water.
Reef-safe sunscreen
Protects skin and marine life in tropical sun; apply before boarding.
summer
Water shoes
Protect feet during rocky entries and while exploring shorelines.
Light wind/rain layer
Useful for cool breezes on the crossing and short tropical showers during the long rains.
spring