Prison Island Tour Zanzibar: Tickets, Prices & Snorkeling

Prison Island — locally known as Changuu Island — sits about 5.6 km off Stone Town, a 20 to 30 minute boat ride depending on the engine and the tide. It's the single most-booked half-day excursion out of Stone Town, and for good reason: you get colonial-era ruins, a tortoise sanctuary, and a swim stop within a three-to-four-hour window.

The name is a bit misleading. No prisoner ever served time here in the way the name implies. The British built a detention block in the 1890s intending to hold recalcitrant slaves and later quarantine cases, but it mostly functioned as a quarantine station for yellow fever and other diseases arriving by ship. That history is worth knowing before you go, because the ruins themselves are modest — a couple of restored buildings, some original walls, and information boards rather than a sprawling complex. If you're expecting a Robben Island-scale historical site, you'll be disappointed; this is a 30-minute wander, not a half-day museum.

What makes the island worth the price of admission is the tortoise sanctuary and, for most visitors, the simple pleasure of a short boat trip with turquoise shallows on either side. It's an easy add-on to a Stone Town stay, and for families with young kids it's one of the few Zanzibar activities that doesn't require much physical exertion or swimming ability.

Historical significance and ruins

The former prison building, constructed around 1893 by the British, was never fully used for its intended purpose — plans shifted to quarantine use almost immediately due to disease outbreaks among ship passengers. Today that same structure houses a small gift shop and a modest history display near the entrance. Walk the perimeter path and you'll find older coral-stone walls dating to the Arab period, when the island was reportedly used to hold slaves awaiting sale, a darker layer of history that predates the British building. Guides will usually cover this in two or three minutes — don't expect a deep narrated tour unless you specifically request a knowledgeable guide or book a tour that emphasizes history over beach time.

Giant Aldabra tortoises and wildlife

The main draw is the colony of Aldabra giant tortoises, introduced from Seychelles in 1919 as a gift and now numbering somewhere in the low hundreds on the island (reports vary year to year due to breeding and occasional losses). Some individuals are reputed to be over 100 years old, identifiable by numbers painted on their shells for tracking. You can get close enough to feed them cut leaves (sold on-site, roughly $1–2 for a bundle) and touch their shells — supervised, since staff keep an eye on enthusiastic children. Beyond tortoises, the island has a small population of Zanzibar red duikers and plenty of lizards, plus decent birdlife along the mangrove fringe if you walk the full loop rather than just the enclosure.

You've got two real options: arrange your own boat from Stone Town's harbor, or book a packaged tour through a hotel, local agent, or platform like GetYourGuide or Viator. Neither is complicated, but they suit different travelers.

Going independent saves money and gives you control over timing — useful if you want to beat the mid-morning rush of tour groups. The trade-off is negotiation. Boat captains at the Stone Town waterfront (near the Forodhani Gardens area) will quote prices that assume you don't know the going rate, and a solo traveler without Swahili will usually pay more per person than a group splitting a boat.

Guided tours cost more but remove the friction — hotel pickup, a set boat, a guide who explains the tortoise feeding and ruins, and a return time you don't have to argue about. For families juggling kids and gear, or couples on a honeymoon who'd rather not haggle on a dock, this is the easier route. It's also the safer bet if you're nervous about boat condition; operators booking through established platforms tend to use better-maintained vessels than the cheapest dockside option.

Self-guided boat logistics from Stone Town

Head to the main harbor area near Forodhani Gardens or the Malindi dhow port any morning between 8am and 11am, when boats run most frequently. Expect to pay in the range of $10–20 per person for a round-trip boat seat if you negotiate reasonably, though solo travelers sometimes get quoted double. The ride takes 20–30 minutes each way in a wooden dhow with an outboard motor. Bring cash in small denominations — nobody on the dock takes cards — and confirm the return pickup time verbally before you hand over money. One real downside: there's no fixed schedule, so you're at the mercy of whenever the boat owner decides to leave, which can mean waiting around on a hot dock for 20 minutes or more.

Organized tour operators and hotel pickups

Most Stone Town hotels and guesthouses can book a Prison Island tour directly, usually bundled with hotel transfer to the harbor. Platforms like GetYourGuide, Viator, and local agents listed on TripAdvisor offer similar packages, typically running 3 to 4 hours including the tortoise visit, ruins, and sometimes a snorkeling stop or Nakupenda Sandbank add-on. These tours remove the guesswork on pricing and timing, and reviews on TripAdvisor are genuinely useful here for weeding out operators with poor safety records. The downside is you're on someone else's schedule — if you want 90 minutes with the tortoises and your tour allots 30, that's what you get.

Pricing for a Prison Island tour in Zanzibar breaks into two layers: the island entrance fee and the boat/tour cost, and conflating the two is how visitors end up overpaying or underestimating the total.

A packaged tour costs more than going independently, but it buys you fixed timing, hotel pickup, and a guide — the island entrance fee of roughly $10 applies either way.

Prison Island Zanzibar tour options compared: cost, duration and what's included

Prices approximate as of 2024-2025; always check current rates when booking, as fuel costs and park fees shift seasonally.

Entrance fees and base tour cost

As of recent seasons, the island entrance fee for foreign visitors runs approximately $10 per adult (children usually half price), paid at the gate regardless of whether you arrived independently or with a group. This covers access to the tortoise enclosure and the ruins. On top of that, the boat transport — whether self-arranged or part of a package — typically adds $15–30 per person for independent bookings, or $25–45 per person for a packaged half-day tour that includes hotel pickup, guide commentary, and sometimes bottled water. Total realistic cost for a no-frills independent trip: around $25–30 per person. A packaged tour with transfers: $35–50 per person. Always check current prices when booking, since entrance fees have crept upward in recent years and boat costs fluctuate with fuel prices.

Additional charges and optional activities

Beyond the base cost, budget for tortoise feed (roughly $1–2), bottled water or snacks if not included, and tips for guides (a few dollars is standard). Snorkeling gear rental, if not included in your package, usually adds $5–10. Some operators bundle a stop at Nakupenda Sandbank into the same outing for an extra $15–25, which is often better value than doing two separate trips since both departures use the same harbor.

Here's the honest trade-off: Prison Island snorkeling is convenient, not spectacular. If snorkeling is the main reason you're coming to Zanzibar, this isn't the place to spend your one big reef day.

Snorkeling conditions and marine life

The water around Changuu Island is shallow and calm, which makes it beginner-friendly and genuinely good for young kids trying snorkeling for the first time. Visibility is decent but not exceptional — think sandy-bottomed patches with scattered coral and reef fish, parrotfish, the occasional small ray, rather than the dense coral walls you'd find elsewhere. Boat traffic in the channel also stirs up sediment on busier days, especially around midday when multiple tour boats converge.

Cost comparison and value assessment

Compare this to Mnemba Atoll, roughly an hour north by boat, where you'll pay more — often $60–80 for a dedicated snorkeling or diving trip — but get noticeably better visibility and healthier coral. If you've got one snorkeling day to spend in Zanzibar, Mnemba wins on quality every time. Prison Island's add-on makes sense if you're already there for the tortoises and ruins and want a cheap, low-effort swim stop rather than a dedicated reef experience — in that context, an extra $5–10 for gear rental is reasonable. If you're a serious snorkeler or diver, save your money and book a Mnemba trip or a reef excursion off Pemba Island instead, both of which outclass Changuu's waters by a wide margin.

Timing matters more here than most Zanzibar activities because the island is small and tour groups arrive in waves.

Seasonal considerations and crowd levels

Zanzibar's dry seasons — June to October and December to February — bring the calmest seas and the most tour traffic. Arrive at the harbor by 8:30am if you want the tortoise enclosure to yourself before the 9:30–11am rush of package tours. Avoid the April–May long rains if possible; boats still run, but rough seas can cancel crossings with little notice, and the ruins' grounds turn muddy. Midday (noon–2pm) is consistently the most crowded window — if you can only pick one thing to control about your visit, control that.

Combination tours with Nakupenda Sandbank

Many operators pair Prison Island with Nakupenda Sandbank, a stretch of exposed white sand about 30 minutes south of Stone Town, as a single full-day package. This works well logistically since both leave from the same harbor area, and it spreads your snorkeling and swimming time across two different settings rather than relying solely on Changuu's modest reef. If you're deciding between a combo tour and two separate bookings, the combo is almost always cheaper and saves a repeat harbor transfer — compare current boat tours and prices before you book, since combined packages vary by operator and season.