Deep Sea and Sport Fishing on the Tanzanian Coast

What deep sea fishing in Tanzania is

Off this coast, the continental shelf is narrow. In several places deep water comes close enough inshore that a boat can be over hundreds of metres within an hour of leaving the beach, and that is the geography the whole activity rests on. Where deep water, current and a reef edge meet, bait concentrates, and where bait concentrates, big pelagic fish hunt.

The Pemba Channel, between Pemba Island and the mainland, is the best known of those places and has a long reputation for billfish. It is not the only one. The water off Mafia, the drop-offs north and east of Unguja, the grounds off Dar es Salaam and the far southern water off Mtwara all fish, and the south in particular sees very few boats.

Fishing here is done from charter boats with a skipper and crew. A day usually means leaving early, running out to the grounds, trolling lures and baits, and returning in the afternoon. Some operations fish light tackle and some fish heavy, some specialise in billfish and some in reef and pelagic species, and those are genuinely different days out.

This coast sits beside Tanzania's safari country rather than inside it. A fishing trip belongs to a coastal week, and the freshwater fishing on the Great Lakes is a separate activity covered in its own guide.

Where the fishing grounds are

The Pemba Channel is the headline ground. The channel is deep, the current runs, and the island's steep western edge concentrates bait. It is the water most associated with large black marlin in this part of the Indian Ocean.

North and east of Unguja, the drop-offs beyond the reef, including the water out past the Mnemba atoll and the banks off the northern tip, give access to pelagic fish within a reasonable run of Nungwi and Kendwa, which is where most Zanzibar-based charters work from.

Off Mafia, the combination of the Rufiji outflow, the deep channel and the reef edges around the marine park produces reef-edge predators as well as offshore species. Large parts of the marine park are managed water, so where you may and may not fish is a real question here rather than a formality.

Latham Island, a small and important seabird island lying well offshore to the south-east of Dar es Salaam, is a long run and a serious day, fished by boats set up for the distance. The southern grounds off Mikindani and the Mnazi Bay area are the least fished water in the country, with correspondingly few boats to fish them from.

What gets caught

The Pemba Channel is credited with six billfish species: black marlin, blue marlin, striped marlin, sailfish, broadbill swordfish and spearfish. That is an unusual spread for one body of water and it is the basis of the channel's reputation.

Beyond billfish, the regular catch across the Tanzanian grounds includes yellowfin tuna, dogtooth tuna along reef edges and drop-offs, skipjack, wahoo, kingfish, giant trevally, barracuda, dorado and a range of reef species on the shallower ground.

What is caught and what you will catch are not the same statement. Any of these fish is possible on the right day in the right water, and a blank day is equally possible. Charters that describe their grounds in terms of what has been caught there are being accurate; charters that describe what you will catch are not.

The shape of the season, and why no month window appears here

The monsoon reversal is the structural driver. The lighter north-easterly kaskazi, roughly December to March, gives the calmest and most consistently fishable sea. The stronger south-easterly kusi, roughly June to September, makes the offshore grounds rough and cuts the number of workable days sharply, particularly for small boats running long distances. On the northern coast and islands the long rains run from around March to May, and many coastal operations close for part of them. The southern grounds off Mtwara sit on a different rainfall calendar, with a single wet season running from around November through to April or May, which is the boundary described in Tanzania's two rainfall regimes.

So the fishable year is broad but weather-broken, and the offshore grounds are most reliably reachable in the calmer half of it.

Beyond that, this guide deliberately gives no month-by-month species calendar, and the reason is worth stating. The published month windows for billfish on this coast come almost entirely from charter operators, and they contradict each other flatly. One page puts black marlin at its peak in one set of months, another puts it in a different set; sailfish are given two separate seasons by different sources; striped marlin gets a window that overlaps neither. No fisheries authority or research body publishes a reachable calendar for Tanzanian waters.

Printing a confident month range assembled from that would look authoritative and would be, at best, a guess. The honest alternative is better anyway: ask the charter you are considering what its own boats caught, and when, over the last two or three seasons. An operation that fishes these grounds keeps that information, and a skipper who can answer it in detail is telling you far more about the fishing than a webpage can.

How it is fished

Trolling is the default. Lures and rigged baits are pulled behind the boat at speed across the grounds, covering water until something takes. It is how most billfish and most tuna are caught here, and it is a day of waiting punctuated by short periods of intensity.

Popping and jigging, working lures vertically or across the surface over reef edges and drop-offs, is the method for giant trevally and dogtooth tuna and is physically hard work. Boats set up for it are a different proposition from a trolling boat, and it is worth asking which you are booking.

Live baiting and drifting is used where bait is concentrated. Bottom fishing on reef ground produces the food fish and is often the fallback when the offshore grounds are not producing or the weather will not allow the run.

Tackle weight matters more than people expect. Light tackle makes an ordinary fish exciting and a large one unlandable within a reasonable time, and long fights are what kill fish intended for release. A skipper who talks about tackle in terms of fight duration rather than trophy size has thought about it.

There is also a much simpler version. Going out with a local crew on a working boat, handlining or trolling a single line, is a completely different and in some ways better day: cheaper in effort, closer to the water, and an honest look at how fishing here actually supports people. It overlaps with the dhow sailing guide and is worth considering by anyone whose interest is the sea rather than the scoreboard.

Catch and release, and what happens to the fish

Most serious charter operations on this coast state that they fish billfish on a catch-and-release basis and follow International Game Fish Association rules. That is the stated norm and it is worth holding operators to it explicitly rather than assuming it.

Release is not automatically harmless. Survival depends on how the fish was hooked, how long the fight lasted, whether it was lifted out of the water, how it was handled and whether it was properly revived alongside before letting go. Circle hooks, short fights, keeping the fish in the water, minimal handling and a proper revive are the things that make release meaningful. A boat that drags billfish aboard for photographs and calls the result catch and release is not doing what it says.

Edible species are generally a different matter, and there is nothing dishonest about keeping fish to eat. Tuna, wahoo, kingfish and reef species are food, and on most boats a share of the catch goes to the crew and to local sale, which is a real part of how these operations work. The reasonable position is to take what will be eaten and release the rest, and to ask the skipper what his boat's practice actually is before the day rather than after.

Shark fishing is worth a direct question. Several species in these waters are under serious pressure and some are protected, and whether a boat targets them, and what it does with them, varies.

Permits, marine parks and where you may not fish

Sport fishing in Tanzania is licensed. Permits for sport fishing, and licensing for sport fishing vessels, sit under the Fisheries Act and its regulations, and a properly run charter handles this as a matter of course. Fees are set by the authorities, change, and are not quoted here. Ask whether your permit is included in the arrangement and, if not, what has to be obtained and by whom.

Marine protected areas impose their own rules on top. Mafia Island Marine Park, Mnazi Bay–Ruvuma Estuary Marine Park and Tanga Coelacanth Marine Park are managed by Tanzania's Marine Parks and Reserves Unit; the Zanzibar conservation areas, including Menai Bay, the Mnemba area and the Pemba areas, are managed separately. Several of these contain no-take zones where fishing is prohibited outright, and others restrict gear or species.

The practical upshot is that "we have always fished there" is not a legal position, and a charter that cannot tell you which zone you will be fishing in and what is permitted there is a charter to be careful with. Zanzibar and the mainland are separate jurisdictions for fisheries purposes, which catches out boats as well as visitors.

Choosing a charter

This site ranks nobody and recommends nobody. These are the questions worth asking.

• What did your boats catch, and when, over the last two or three seasons?
• Is this a trolling boat, a popping and jigging boat, or both?
• What is your practice on billfish: circle hooks, fish kept in the water, revived before release?
• What happens to fish that are kept?
• Do you target sharks?
• Which zone will we be fishing in, and what is permitted there?
• Are permits included, and what is payable to whom?
• What safety equipment is on board, and does the boat carry a radio, an EPIRB or a satellite communicator for the longer runs?
• How many anglers share the boat, and how many rods fish at once?

The longer runs, to Latham or the outer grounds, raise the safety questions rather than lower them. A boat going a long way offshore should be able to call for help from out there.

Comfort, seasickness and what to take

Offshore days are long, hot and frequently lumpy, and seasickness accounts for more ruined charters than poor fishing does. Anyone who is prone to it should start medication the night before rather than on the dock, and should be aware that the worst of it is usually the slow trolling rather than the running.

Take sun protection well beyond what feels necessary, because there is little shade on most boats and the light comes off the water all day. Long sleeves, a brimmed hat and polarised sunglasses are the standard three, and polarised lenses genuinely help you see fish as well as saving your eyes. Take more water than provided. Soft-soled shoes. A dry bag for anything electronic.

Check what the boat provides. Tackle, bait, ice, lunch and drinks are included on some charters and not on others, and gloves for handling line are worth having regardless.

Common questions about deep sea fishing in Tanzania