Sandbank Trips and Island Hopping in Tanzania

What a sandbank actually is here

A sandbank on this coast is not a small island. It is a bar of sand that sits below the surface at high water and emerges as the tide drops, exists for a few hours as a strip of dry ground in open sea, and then goes back under. Some are large enough to walk the length of. Some hold a dozen people and no more. Their shape changes between visits and a few of them move.

That impermanence is the whole appeal. Standing on dry sand with open water on every side and no land in sight is an odd and memorable thing, and it exists nowhere except on this kind of coast, on this kind of tide.

Island hopping is the related but different activity: moving between the real islands off Unguja, Mafia, Pemba and Dar es Salaam, most of which are small, some of which have ruins or forest or a colony of something, and several of which cannot be landed on at all. In practice the two get sold together, because a day on the water usually takes in one of each.

This coast sits beside Tanzania's safari country rather than inside it, and a sandbank day belongs to a beach week.

The tide, and the safety consequence

Zanzibar runs a semidiurnal tide, two highs and two lows a day, with a range from around a metre at the neaps to over three metres at the springs. A sandbank's entire existence is a function of that.

Practically, that means three things.

First, sandbank trips run to the tide, not to the clock. A trip that can leave at nine on Tuesday may need to leave at six or at one by Friday, because low water moves roughly fifty minutes later each day. An itinerary that ignores this gets rewritten for you, and a boat that insists on a fixed departure regardless of the tide is either going somewhere else or arriving at a sandbank that is under water.

Second, the largest sandbanks appear around the spring tides and some of the smaller ones barely appear at the neaps at all. Over a fortnight, the same place is a beach, a shoal and nothing.

Third, and this is the one that matters: the water comes back. It comes back around you rather than towards you, faster than a flat surface makes it look, and every year somebody is caught out by it. Never let a boat leave you on a sandbank without a firm agreed return time. Know when the turn is. If the crew is wading to reach the boat, you are already late.

Where the sandbanks are

Off Stone Town and the west coast, the bars in the channel between the town and the small islands are the most visited, the easiest to reach and the busiest. Nakupenda, off the south-west of Unguja, is the best known and typically combined with a stop at Changuu or Bawe.

In Menai Bay, off Fumba and the south-west, the bars around Kwale and the surrounding shoals give a longer, quieter day with better water and fewer boats.

Off the north-east, the sand around the Mnemba atoll is the most photographed in the country. Further up the east coast, bars appear on the outer edge of the reef flats at Matemwe, Paje and elsewhere at low water, some reachable by wading rather than boat.

On Mafia, sandbanks emerge inside and around Chole Bay and out towards the Shungimbili, Nyororo and Mbarakuni marine reserves. Around Pemba, bars appear in the shallows near Misali and off the west coast.

On the mainland, Maziwe, off Pangani, is a sandbank island inside a marine reserve and an important seabird and turtle site, which places some limits on what you can do there. Off Dar es Salaam, the sand around Fungu Yasin and the Dar es Salaam marine reserve islands gives the easiest sandbank access from a Tanzanian city.

Island hopping, and which islands you can actually land on

The islands off Unguja make the most common hopping circuit. Changuu, widely called Prison Island, has ruins, a short forest walk and a managed colony of Aldabra giant tortoises, which are a captive population rather than a wild one and are often described loosely as if they were not. Chapwani is small, quiet and has an old cemetery. Bawe is the snorkelling stop.

Chumbe is different in kind. It is a privately managed reef sanctuary and forest reserve established in 1994, with a strictly capped number of visitors and a booking process to match. It cannot be added to a boat's itinerary on the day, and that restriction is precisely why the reef there is in the condition it is.

Mnemba is the one people most often misunderstand. The atoll's water is a conservation area and a major snorkelling and diving site. The island itself is private and not open to day visitors. A trip sold as "Mnemba Island" is a trip to the water around it, and it is worth having that clear before you go rather than discovering it from the boat.

Off Mafia, Chole and Juani are both reachable and both have substance: Chole has the ruins of a nineteenth-century settlement under enormous fig trees, and Juani has the Kua ruins and is the most important green turtle nesting beach in Tanzania, which brings its own restrictions in season. Off Pemba, Misali sits inside the Pemba Channel Conservation Area as a no-take zone, and has landing beaches as well as reef.

Off Dar es Salaam, Bongoyo, Mbudya, Pangavini and Sinda form a marine reserve system and are the standard weekend escape from the city, with boats running from the mainland shore.

Inland, the freshwater equivalent exists too. Lake Victoria has Ukerewe, Napoleon and the Saa Nane and Rubondo island parks, reached by boat from Mwanza, and it is a genuinely different kind of island day.

What a trip looks like

The standard half day runs out to a reef for snorkelling, then to a sandbank as the tide falls, then back. The standard full day adds a second reef, an island landing and a lunch, which on the better-organised trips is grilled fish and rice cooked on the boat or on the beach.

Boats range from small motorised mashua carrying half a dozen people to larger boats carrying thirty or more, and the difference in the experience is considerable. A sandbank with eight people on it and a sandbank with four boats' worth of people on it are not the same place.

Some sandbank trips are sold with furniture: a table, chairs, a shade canopy, sometimes a full lunch setup carried out and assembled. That is a genuinely lovely way to spend three hours and it is worth knowing in advance whether it is what you are getting, because the same destination is sold both ways.

The in-water half of the day is covered in the snorkelling guide, and the boat itself in the dhow sailing guide.

Sun, shade and the thing everybody underestimates

A sandbank has no shade. None. It is white sand in open water within a few degrees of the equator, and the light comes at you from above and off the surface at the same time. Two hours on one will burn people who thought they were being careful, and it is the single most common way to ruin the following three days of a holiday.

Take more than you think: a long-sleeved rash vest or shirt, a hat with a brim, sunglasses, reef-safe sunscreen applied before you leave and reapplied on the boat, and something to sit on other than the sand, which gets hot. Take water, and more of it than the boat provides. If the trip does not carry a shade canopy, ask, because on some boats it is available and simply not brought unless requested.

Footwear matters more than it looks like it should. Getting to and from the boat usually means wading over reef rubble or seagrass, where long-spined sea urchins sit invisibly, and reef shoes remove the problem.

Conduct on a sandbank

A sandbank looks like nothing lives there, and that is misleading. Several are seabird roosting and nesting sites, and Maziwe in particular is a protected island for that reason. Turtles nest on the larger sand islands, including Juani off Mafia. Walking through a nesting area, or a group of roosting birds, does real damage for no gain.

The rest is simple. Take everything off with you, including fruit peel, which does not belong there and attracts gulls. Do not collect shells, which on a protected coast is frequently illegal as well as pointless. Do not let the boat anchor on coral; a sand bottom is always available and a crew that knows its water will use it. Keep noise down, since a sandbank carries sound a long way across flat water and is often shared.

Several of these islands and bars sit inside marine parks, conservation areas or reserves with fees payable to the managing authority. Those fees change and are not quoted here, for the same reason that the national park and Ngorongoro tariffs are kept in one dated, sourced place rather than repeated across the site. Ask what is payable and to whom before you go.

Choosing a boat

This site ranks nobody and recommends nobody. The questions that matter are short.

• What time does the boat leave, and is that time set by the tide? If the answer is not about the tide, ask again.
• How many people are on board?
• Is there shade on the boat and on the sandbank, and is there drinking water?
• Are there lifejackets for everyone, and a working phone or radio?
• What is the agreed return time from the sandbank, and who is keeping track of it?
• Which islands do we actually land on, as opposed to pass?
• Are conservation area or marine park fees included, and if not, what is payable?

Book through your accommodation or a licensed operator rather than off the beach. That is about having somebody to go back to if the day is not what was described, not a comment on anyone's honesty.

Common questions about sandbank trips and island hopping