Zanzibar tides: why the sea disappears, and which beach to choose
On Zanzibar's east and southeast coasts, the sea can retreat several hundred metres twice a day, leaving a flat expanse of sand, seaweed and coral where the water was three hours earlier.
This surprises a great many visitors, and it surprises them after they have booked. Hotels rarely mention it. Photographs never show it.
It is not weather, it is not seasonal, and nothing has gone wrong. It is tide, it is entirely predictable, and once you know which coast does what, you can plan around it completely.
Why the sea goes so far out
[EXTERNAL SOURCE NEEDED] Attribute the tidal range figures below to an official hydrographic or meteorological source before publishing.
Two things combine.
The first is the reef. Much of Zanzibar's east coast sits behind a fringing coral reef several hundred metres offshore. Between the beach and that reef lies a shallow lagoon, and the lagoon floor is close to flat.
The second is tidal range. Zanzibar has a substantial one, in the region of three to four metres at spring tides. Drop the water level by three metres over a lagoon floor that barely slopes and the water does not go down, it goes out.
On the north and west coasts the seabed shelves away more steeply and there is less lagoon to drain, so the same tidal range produces a far smaller change in where the water's edge sits.
Two highs and two lows, moving daily
Zanzibar has semi-diurnal tides. Two high waters and two low waters roughly every 24 hours, with about six hours between each stage.
The important practical point is that the timings shift by roughly 50 minutes each day. The low tide that was at 09:00 on Monday is closer to 10:40 by Wednesday. You cannot learn the pattern once on arrival and rely on it for the week.
Spring tides and neap tides
Around the full moon and the new moon, the range is at its greatest. These are spring tides, and they produce both the furthest retreats and the fullest high waters.
Around the first and last quarter moons, the range is smallest. These are neap tides, and the difference between high and low is much less dramatic.
If uninterrupted swimming matters to you and your dates are flexible, a trip timed near a quarter moon on the southeast coast will feel very different from one timed on a full moon.
Coast by coast
This is the part worth reading before you book accommodation.
Nungwi and Kendwa, the north
The least affected beaches on the island, and Kendwa in particular is swimmable at essentially any state of tide.
If your priority is walking out of your hotel and into deep water at any hour, this is where to stay. It is also the busiest and most developed part of the coast, which is the trade-off.
Matemwe and Kiwengwa, the northeast
Moderately affected. The reef sits well offshore and low tide is clearly noticeable, but the retreat is less extreme than further south.
Matemwe is the launch point for the Mnemba reef, so if snorkelling is the point rather than beach swimming, the tide matters less to you anyway.
Paje, Jambiani and Bwejuu, the southeast
The most dramatic tidal coast on the island, and the one people mean when they complain online.
At low tide the water can be several hundred metres out and the lagoon becomes a walkable flat. This is where the seaweed farms are, worked mostly by women, and the sight of the harvest lines with figures moving between them is one of the genuinely memorable things on Zanzibar.
It is beautiful. It is not swimming.
If you are staying here, plan your swims for the hours either side of high water and use the rest of the day for everything else. Do not book here expecting to swim on demand.
The Michamvi peninsula
Varies along its length, and the west-facing side at Michamvi Kae behaves differently from the exposed eastern shore.
Michamvi Kae is also the only spot on this side of the island where you watch the sun set over water, which is worth the drive regardless of the tide.
Kizimkazi and the south
Moderate. Less extreme than Paje, and most visitors here are going out on boats rather than swimming from the beach.
Stone Town and the west
Minimal tidal drama, but this is not a swimming coast in any case. The beaches near town are working waterfront rather than holiday beach.
Low tide is not a wasted afternoon
The framing that helps is to stop thinking of low tide as the sea being gone and start thinking of it as a different place appearing.
Walk out. On the southeast coast you can walk most of the way to the reef, through tide pools, past starfish and sea cucumbers, over sandbars that only exist for a few hours.
Watch the seaweed farming. It is a significant local industry and it happens at low tide, right in front of you. Watch from a distance, do not walk over the drying harvest, and ask before photographing anyone working.
Photograph it. The flat wet sand at low tide with the sky reflected in it is the shot people bring home, more than the postcard blue water.
Learn to kitesurf. The shallow lagoon at Paje is exactly why it became a kitesurfing centre. Standing depth over a sandy floor is a far more forgiving place to learn than deep water.
Go somewhere else for a few hours. This is the practical answer, and it is why a car changes the shape of a beach holiday here. Low tide at Paje is a good moment to be at Jozani, in a cave, or on the road to Michamvi.
What is reachable and how long it takes: Zanzibar by car
Wear something on your feet
The lagoon floor is coral rubble, shells and sea urchins.
Sea urchin spines are the most common injury visitors pick up on this coast, and they are painful, awkward to remove and entirely avoidable. Reef shoes cost very little, are sold everywhere on the island, and should go on before you walk out.
Do not stand on live coral, and do not pick anything up to take home. Taking coral is illegal, and shells are somebody's ecosystem rather than a souvenir.
More on this: Zanzibar dos and don'ts
Tides govern more than swimming
Several of the island's headline experiences are timed by water rather than by you.
The Rock Restaurant. You wade across at low tide and take a small boat at high tide. Both are fine, but the tide decides which, and your reservation time determines the experience.
Nakupenda sandbank. It exists at low tide and is under water at high tide. Trips are scheduled around it, which is why they cannot be moved to suit you.
Boat departures generally. Snorkelling trips, dhow cruises and dolphin trips all launch on the water they have. Departure times that look arbitrary are usually tidal.
Sunset dhow trips. Where a boat can leave from, and how far it has to be walked out, depends on the state of the tide that evening.
How to plan around it in practice
Get a tide table for your dates before you travel. Search for tide times for the nearest named point to your hotel rather than for Zanzibar generally, since the timings differ around the island.
Check the moon phase. Full or new moon means the biggest range. Quarter moons mean the mildest.
Match your coast to your priority. Guaranteed swimming means the north. Landscape, kitesurfing, quiet and lower prices mean the southeast, with swimming around high water.
Ask your hotel for the day's times on arrival. They know, they will tell you, and it takes ten seconds.
Build the day around the water rather than against it. High water for swimming, low water for walking out or driving somewhere else.
Frequently asked questions
Why is the sea so far out in Zanzibar? The east and southeast coasts sit behind a fringing reef with a shallow, almost flat lagoon between the beach and the reef. A tidal range of roughly three to four metres drains that lagoon, so the water's edge moves out hundreds of metres rather than down.
Which beach in Zanzibar is best for swimming at any tide? Kendwa on the north coast, with Nungwi close behind. Both are far less affected by the tide than the southeast beaches.
Can you swim in Paje at low tide? Not really. The water retreats several hundred metres and what remains is ankle to knee deep over coral rubble. Swim around high water instead, and use low tide for walking out, kitesurfing or driving elsewhere.
How often does the tide change in Zanzibar? Two high tides and two low tides in roughly every 24 hours, with the timings shifting about 50 minutes later each day.
Do I need reef shoes in Zanzibar? On the east and southeast coasts, yes. The lagoon floor has coral rubble and sea urchins, and urchin spines are the most common injury visitors pick up here.
The tide is the single thing most likely to shape a beach holiday here, and it is also the easiest to plan around once you know it exists. If you are deciding how to move between coasts to chase the water, our guide to driving in Zanzibar covers the practical side.
Tidal ranges are approximate and vary through the lunar cycle. Always check a current tide table for your specific location and dates.