28 Best Places for Scuba Diving in World

The best dive of your life is probably not the one you expect. It might be a quiet drift along a wall in Cozumel where an eagle ray glides past without a glance, or a night in Bonaire when tarpon hunt in your torch beam. It might be a clattering week on a liveaboard in the Galápagos where hammerheads rise out of the blue, or a muddy hour in Lembeh watching a mimic octopus become a flatfish. The ocean is generous with surprises, and the best way to meet them is to choose a place that matches how you dive rather than where the brochures send you.

This guide is built around that idea. Instead of one flat ranking, it follows divers through the stages of their journey, from the shallow reefs where you learn, to the currents that test you, to the caves and wrecks that demand training, and then to the remote places that most people only see in films. Each destination gets a short story, a compact dive file with the facts you need and a few honest notes about what can go wrong. Further on you will find a scored ranking, a month-by-month calendar and a chapter on the things brochures leave out, such as how far you are from a recompression chamber and why the moon matters as much as the month.

Treat the numbers as a planning aid, not a promise. Seasons shift, permits change and conditions on the day can overrule any guide. But if you read the stories, pick two or three places that call to you and check the details with a good operator, you will be far better prepared than most.

Bonaire is a destination that seems to have grown out of an island's habit of looking after its own coastline. Drive the single road along the leeward shore and you will pass small yellow stones painted beside the tarmac, each one naming an entry point: Something Special, Windsock, Salt Pier. Pull a pickup onto the gravel, carry your gear down to the water's edge and simply walk in. There is no boat to catch and nobody hurrying you toward a second dive when you would rather hang over the first one a little longer.

The reef begins almost at your fins, a gentle slope of hard corals and sponges that tumbles into the blue within a few minutes of kicking. Parrotfish crunch on coral with an audible rasp, juvenile drumfish flutter like punctuation marks under ledges, and turtles surface and settle again as though following a timetable of their own. After dark the same sites become a different place entirely, with tarpon hunting in the beam of your torch and octopus slipping across the rubble.

Because the whole coastline is a protected marine park, you will pay the annual nature fee, follow the rules about touching and anchoring, and quickly notice how well the reef rewards that discipline. Bonaire suits people who want to dive often, dive slowly and build confidence without anyone watching the clock, and it is one of the few places where a certified diver can plan an entire week of self-paced shore diving with a buddy once the local orientation is done.

Cozumel teaches you to let go. The first time a guide explains that the current will carry the group along the wall while the boat follows your bubbles, there is a flicker of unease, and then the dive begins and the unease dissolves. You roll off the side, drop onto the edge of the Mesoamerican Reef, and the island simply conveys you past canyons of sponge, coral buttresses and swim-throughs with your fins barely moving.

Palancar and Columbia are the walls everyone mentions, towering structures dotted with barrel sponges the size of armchairs, and the visibility often lets you read the whole architecture of the reef in a single glance. Eagle rays glide along the drop-off with the ease of birds, hawksbill and green turtles nibble at sponges, and in the shallows you may spot the splendid toadfish, a bug-eyed little creature found nowhere but around this island, sulking beneath its ledge.

Logistics are smooth because Cozumel has been organising dive tourism for decades: day boats leave from the waterfront in San Miguel, you are back in time for lunch, and tacos in the evening feel earned. The one discipline drifting asks of you is to carry a surface marker, stay close to your guide and never assume the boat can see you until you have inflated it. Visit between November and May and the weather is gentle; arrive in hurricane season and you gamble with cancelled ferries and rough crossings.

The Red Sea is the great generalist of the diving world, and that is exactly why it sits at the top of our ranking. The water is warm, the visibility often rivals the Caribbean, and the infrastructure is so well developed that a week of diving here costs a fraction of what the same week would cost in the Pacific. Start gently. At Dahab or Sharm El Sheikh you can walk from your room to a shallow house reef, where anthias shimmer over coral heads like sparks off a fire and lionfish hover in the shade of overhangs.

When you are ready for more, boats carry you to the walls and pinnacles of Ras Mohammed, where schools of fish swirl in the current, or south to Marsa Alam, where the calm bays are a good place to look for turtles and, with luck, a grazing dugong. The water is so clear and so salty that colours seem to hold their saturation deeper than almost anywhere else, and the reefs can be a riot of soft coral in shades of pink, orange and violet.

There are cautions worth stating plainly. The shore entries in Dahab are easy, but the famous Blue Hole there has a long record of accidents involving divers who drifted deeper than they had planned, so treat it with respect or skip the arch altogether. Boat traffic can be heavy in peak season, so pick operators that limit group sizes. Spring and autumn are the most comfortable months, and the best strategy is to base yourself in one town for at least five days so you can progress from house reef to wall to wreck without rushing.

Some wrecks demand a long boat ride and a leap of faith. The USAT Liberty asks only that you cross a black-sand beach in Tulamben and wade in. The US Army cargo ship was torpedoed in 1942 and beached on this shore, and when Mount Agung erupted in 1963 the shaking and lava slid her into the sea, where she has been collecting coral and fish ever since. Today she lies a short swim out, her upper structure in shallow water and her stern dropping toward deeper blue, which is why she suits everyone from careful beginners to photographers who want hours of light on a single subject.

Timing is everything here. By mid-morning the dive boats and shore groups arrive and the wreck gets busy, so the people who enjoy her most are the ones who enter at first light, when the water is calm, the sun slants through the hull and a school of bumphead parrotfish often sweeps in to feed. A second dive after the crowds leave, or a night dive when the wreck belongs to sleeping fish and hunting crustaceans, shows you a completely different ship.

Tulamben is only one chapter of Bali's diving. Nearby Amed and the Kubu coast offer calm muck dives and Seraya Secrets, a shallow site beloved by photographers; Padangbai's Blue Lagoon is a gentle place to train; and between July and September, Nusa Penida draws mola mola and, in season, manta rays. We have mapped these in more detail in our guide to the best scuba diving sites in Bali, including the months that work best. One practical note: if your route back to the airport crosses high ground, remember that altitude after diving follows the same decompression logic as flying, so check the road before you pack the car.

Getting to the Andamans is part of the story. You fly into Port Blair, climb onto a ferry crowded with backpackers and local families, and watch the water change from harbour grey to a green that grows steadily more transparent as Havelock Island rises out of the haze. The island, officially Swaraj Dweep, has become the heart of Indian scuba diving, a place where first-timers surface from their very first breath underwater grinning as if they had discovered a secret.

The shallow reefs near Elephant Beach and Nemo Reef are gentle enough for introductory dives, with soft corals, anemonefish and schooling fusiliers within a few metres of the surface. Move on to Dixon's Pinnacle, Johnny's Gorge or the pinnacles off Neil Island and you meet currents, larger fish and the feeling of diving in open water. The warm, clear conditions between November and April keep the archipelago comfortable all day, and many operators run courses that let you complete certification in three or four days, often at a fraction of what the same course would cost in Europe or the Caribbean.

The caveats are practical rather than dramatic. The monsoon from May to October brings rough seas and closes many sites, so plan your trip around the dry season. Medical facilities are limited outside Port Blair, which makes a conservative dive profile wise, and permit rules for visitors have changed over the years, so check the latest requirements before you book. For divers based in India this is the easiest way to find out whether you love the sport, with direct flights from several major cities. For a wider look at the country's coastline, see our guide to the best places to scuba dive in India.

The Galápagos asks more of you than almost any dive destination, and gives back more than most. Darwin and Wolf lie far to the north of the main islands, and the only way to dive them is aboard a liveaboard that spends the better part of a day crossing open ocean. You arrive at dawn to see a rock rising from the sea, birds wheeling above it, and a swell that already tells you this will not be a gentle experience. Then you pull on a thick wetsuit, roll backwards from a panga and drop straight into the blue.

The reason for the thick suit is the water. Cold upwellings from the Humboldt Current can drop the temperature to sixteen or eighteen degrees Celsius even when the equatorial sun is baking the deck, so a hood and gloves are not luxuries but tools for staying focused. The current is strong, entries are often negative, and surge pushes you back and forth along the wall. In return, hammerhead sharks arrive in schools of dozens, Galápagos sharks patrol the edges, eagle rays cruise by in formation, and from June to November whale sharks, many of them pregnant females the size of a bus, glide past like slow ships.

A famous landmark changed here in 2021, when Darwin's Arch collapsed, leaving two pillars standing in the blue. The site still carries the name and still draws the sharks. Because the Galápagos is a national park, you pay an entry fee, follow strict rules and dive with licensed operators. Expect operators to ask for around fifty logged dives, and bring a surface marker and a guide who briefs on emergencies, because a drifting diver in this ocean is very hard to find.

Socorro is what many divers picture when they imagine the open Pacific. The Revillagigedo Islands sit roughly four hundred kilometres or more from the tip of Baja California, and reaching them means a night and most of a day aboard a liveaboard heading out into blue. There are no resorts, no villages and no other boats on the horizon. There is only a small group of volcanic islands, a UNESCO-listed marine reserve, and an ocean full of animals that have rarely been bothered by people.

At El Boiler, off San Benedicto, giant Pacific manta rays come to be cleaned and often turn toward divers with unmistakable curiosity. Their wingspans can reach several metres, and an encounter in which a manta hovers a metre away, tilting its eye toward you, is the reason many people book the trip. At Roca Partida, a tiny pinnacle covered in fish, whitetip reef sharks pile up in resting groups on ledges while silky sharks and occasionally tiger sharks circle the rock. Dolphins visit boats and divers on many days, and in winter humpback whales arrive and their songs fill the water.

The diving is demanding. Currents can be strong, swell reaches the rock from every direction, and entries are typically quick and negative from a small skiff. Operators usually require Advanced certification and recent experience, and for good reason: this is the ocean at its most beautiful and its least forgiving. Pack a surface marker, a thicker suit than you think you will need, and the patience for a long crossing. The reward is a week that divers often describe as the best of their lives.

Palau feels like a place that decided long ago that its reefs mattered more than anything else it could sell. The country created the world's first national shark sanctuary in 2009, and the conservation attitude shows in everything from the pledge stamped into your passport on arrival to the way operators brief you before every dive. Fly into Koror and you step into a landscape of rounded limestone islands floating on turquoise water like green mushrooms, the Rock Islands Southern Lagoon, a UNESCO World Heritage Site.

Blue Corner is the dive that made Palau's name. You drop to a wall at the edge of the reef, clip a reef hook to the dead rock and hang in the current like a kite while grey reef sharks, barracuda, big-eye trevally and Napoleon wrasse stream past. The hook is not an accessory but a technique, a way to stay still in a tide that would otherwise carry you along the wall, and learning to use it without damaging coral is part of the experience. When the current eases, German Channel and Ulong Channel offer calmer drifts, and Peleliu Wall pairs a sheer drop with a haunting history from the Pacific war.

Plan your trip around the moon. Around full moons, groupers and other reef fish gather at spawning sites to release their eggs, and sharks follow, but the same lunar tides create strong, washing-machine currents that suit experienced divers more than beginners. Fees are part of the deal here: a visitor environmental fee and a Rock Islands permit are required, and they help fund the patrols that keep the reefs healthy. Palau is not cheap, but it is one of the few places where you can see how a small nation can protect an entire ocean.

Sipadan is a volcanic pillar that climbs from some six hundred metres of water to a small island fringed with white sand, and the dive begins long before you hit the water. You approach by boat from Semporna or Mabul, watch the palm-fringed outline grow and feel the thrill of arriving somewhere that has been protected for a reason. The island's own resorts closed years ago to safeguard its ecosystem, and today access is controlled by a strict daily permit system. Only about a hundred and twenty divers a day are allowed to dive here, which is why it feels like a privilege rather than a product.

Barracuda Point is the dive that justifies the permit. A school of barracuda forms a slowly rotating tornado around you, so dense that it cuts out the light, while jacks and bumphead parrotfish patrol the wall. Beneath the island, Turtle Cavern is a labyrinth with a legendary history of turtle skeletons, though today the dive is mostly about the sheer number of green and hawksbill turtles resting on the reef or surfacing to breathe, often within arm's reach. Hanging Gardens, South Point and the drop-off add variety, and you often finish with a gentle shallow drift.

Plan early. Operators must secure your permit in advance, and the rules on certification, number of dives and site rotation have tightened in recent years: under the notice that took effect in October 2022, Advanced Open Water was required, each permit allowed two dives, and fees for non-Malaysians rose to RM350 per day. Rules change, so confirm everything with your operator. And while Sipadan is the star, the surrounding Mabul and Kapalai reefs are macro paradises, so a week split between muck and pelagics is the best way to see the full picture.

The Great Barrier Reef is less a single reef than a living landscape of nearly three thousand individual reefs stretching for more than two thousand kilometres along the Queensland coast. No single trip can cover it, so the question is not whether to dive it but where. Most travellers start from Cairns or Port Douglas, board a day boat or liveaboard and head out to reefs where coral gardens, bommies and walls offer everything from gentle first dives to adrenaline-heavy drifts.

The Ribbon Reefs, strung along the outer edge, are home to the Cod Hole, where enormous, friendly potato cod come right up to divers, and to Pixie Pinnacle and Steve's Bommie, towers of coral and fish. In June and July, dwarf minke whales visit the northern Ribbon Reefs, and encounters with them are among the most sought-after wildlife experiences in Australia. Farther out, Osprey Reef in the Coral Sea offers sharks and sheer walls, and in the south, Heron Island and Lady Elliot Island are known for turtles and manta rays.

Honesty matters here. Parts of the reef have suffered repeated mass bleaching events in recent years, so quality varies from site to site, and good operators will tell you which areas are healthy. Seasonal timing also matters: from roughly November to May, stinger jellyfish are a risk inshore and a stinger suit is advised, while June to November brings drier weather and calmer conditions. For a truly special week, plan around the annual coral spawning, which typically takes place a few nights after the full moon between October and December, when the reef releases clouds of pink and orange eggs into the water.

Diving a cenote is like swimming through a cathedral that someone filled with water. You walk down a wooden stairway into a sinkhole in the jungle, step onto a platform at the water's edge and look down into a clarity that makes the surface feel like a layer of glass. Sunlight pours through holes in the roof in solid-looking shafts, and as you glide beneath them the water around you glows blue and green. The Yucatán Peninsula has thousands of cenotes, formed when limestone collapsed above a vast network of underground rivers, and dozens are open to recreational divers near Playa del Carmen and Tulum.

The signature moment is the halocline, the line where fresh water sitting on top of denser seawater meets in a shimmering, blurred layer that makes your hands look as if you are viewing them through a heat haze. Cenote Angelita adds a strange twist, a cloud of hydrogen sulfide at around thirty metres that looks like a river flowing across the bottom of the sinkhole, with a stand of dead trees poking through. Dos Ojos, Gran Cenote and Chikin Ha are among the best-known sites for cavern diving, where stalactites and stalagmites decorate passages that remain within sight of daylight.

The rules are the most important part of the story. Cavern diving, in which you stay within the daylight zone and a guide leads you, is open to certified divers, but passing beyond that zone into the true cave requires dedicated cave training and equipment, and untrained divers have died here. Fresh water is less buoyant than the sea, so you will need less weight than you are used to, and the stable temperature of about twenty-five degrees Celsius means a thin suit is enough. Because there are no currents and no waves, cenotes are also an excellent place to hone buoyancy and trim.

In February 1944, a two-day American air and naval assault known as Operation Hailstone sank dozens of Japanese ships in the lagoon of Chuuk, then called Truk. Their wrecks lie where they fell, and today the lagoon is considered one of the greatest wreck diving destinations on Earth. You reach it by a long flight through Guam, check into a small hotel or a liveaboard and spend your days descending onto decks that are now draped in soft coral and encrusted with sponges.

Fujikawa Maru is the classic introduction, a cargo ship in around thirty metres of water whose holds still contain aircraft parts and equipment, and whose masts rise to a depth where you can wander at length without leaving recreational limits. Shinkoku Maru is a tanker covered in coral and fish, and San Francisco Maru, deeper still, holds tanks and mines that are the realm of technical divers. Inside the wrecks you might see gas masks, bottles, plates and even boots, which gives the dives an eerie sense of being in a time capsule. Because the lagoon is protected by a ring of reef, conditions are generally calm and the water is warm.

The sites are war graves and historic artifacts, so look but do not take. Wreck penetration requires training, and many of the best sites sit at the edge of recreational depth, so Advanced certification, good buoyancy and a conservative approach are essential. Technical gases such as trimix, or rebreather support, must be arranged well in advance. The nearest reliable hyperbaric chamber is far from the lagoon, so plan with a safety margin. Divers who respect these limits find that Chuuk is not only a place to see ships but a place to think about the people who sailed them.

From the air, the Great Blue Hole looks like an eye staring up from the sea, a perfectly round, dark blue sinkhole set in a ring of pale turquoise reef. Jacques Cousteau helped make it famous in 1971, and it remains one of the most recognisable dive sites in the world. You reach it from Belize City or Ambergris Caye on an early morning boat that crosses open water for a couple of hours, arriving at Lighthouse Reef, where the hole sits at the heart of the atoll.

The dive itself is an exercise in discipline. You descend to roughly forty metres, where giant stalactites, formed when this was a dry limestone cave during the last ice age, hang from an overhang in the wall. The light is dim, the water cools slightly, and your computer ticks quickly toward the no-decompression limit, so you spend only a few minutes before beginning a slow ascent. Reef sharks sometimes drift through the gloom, but most people come for the geology and the feeling of descending into a place that once stood above sea level.

Divers sometimes say the Blue Hole is the least colourful dive of the trip, and they are right. That is why operators pair it with Half Moon Caye Wall and Long Caye Aquarium, shallower dives with turtles, eagle rays, reef sharks and dense fish life. Add Turneffe Atoll, Hol Chan and Gladden Spit, the whale shark site that gathers divers around the full moons from spring into early summer, and Belize becomes a week of varied diving. Because the Blue Hole is deep and far from shore, it is a dive for experienced divers with good air consumption, and the rule is simple: stay within your plan and accept that the clock is the boss.

Cocos Island is the kind of place that starts as a rumour. Pirates are said to have buried treasure here, the island is often linked with the legend behind Treasure Island, and for most of the last century nobody lived on it except rangers. Today it is a national park and a World Heritage Site, floating some five hundred kilometres off the Pacific coast of Costa Rica, and the way to reach it is a liveaboard that sails for roughly thirty-six hours from Puntarenas through open ocean.

The reward is one of the great shark dives. At Alcyone, a submerged seamount, schools of scalloped hammerheads gather at cleaning stations in numbers that can reach dozens at once, hanging in the current as small fish remove parasites from their skin. At Dirty Rock, a rocky islet, whitetip reef sharks, eagle rays, big schools of jacks and sometimes giant manta rays patrol the walls, and at Manuelita you can look for marbled rays and octopus in the shallows. Conditions are demanding, with swell, current and sometimes cold thermoclines, and the skiffs that carry you to the sites bounce through the waves.

Because the ride is long and the reefs are far from help, Cocos demands preparation. Seasickness tablets are worth packing, as are a surface marker and a dive computer you trust, and your insurance must cover evacuation from a remote site. Visit between June and November, when the rains bring hammerheads in numbers but also rougher seas, or between December and May for calmer water and fewer sharks. Either way, the encounters are natural rather than baited, which is increasingly rare. Cocos is an expedition rather than a holiday, and divers who make the journey rarely forget it.

The Maldives look unreal from the seaplane: a scatter of tiny green islands surrounded by rings of turquoise lagoon, with the dark blue of the open ocean beyond. For divers, the real action is in the channels, or kandus, where the sea pours in and out of the atolls twice a day. These channels act like conveyor belts, bringing plankton and small fish and, behind them, grey reef sharks, whitetip sharks, eagle rays, napoleon wrasse and turtles. Diving here is less about wandering over a reef and more about picking a spot on the edge of a channel and watching the ocean come to you.

In the dry season from roughly November to April, the water is calm and clear, and most of the famous sites, such as Maaya Thila and Banana Reef in the North Malé Atoll, are at their best. In the wetter months from May to November, plankton blooms in some atolls bring manta rays and whale sharks to feeding sites, but they also reduce visibility, so you must choose between clearer water and bigger animals. Hanifaru Bay in Baa Atoll is famous for its manta gatherings, but it is a protected area where only snorkelling is allowed, so divers should look to other manta cleaning stations.

Choose your style of trip wisely. House-reef resorts offer relaxed, comfortable diving close to your room, while liveaboards cover far more ground and reach remote atolls, often at better value per dive. Strong currents are normal, so you must be comfortable with drifting, using a surface marker and, at some sites, hooking in. Daily rates vary enormously between a basic guesthouse on a local island and a luxury resort, and a green tax is charged per night. Whichever route you pick, the Maldives rewards divers who time their trip to the season of the animals they want to see.

At Ningaloo, the reef comes to you. Unlike most reefs, which lie far offshore, Ningaloo's fringing coral begins just a few metres from the beach, and some of the best snorkelling in Australia is a short swim from the sand at places such as Turquoise Bay. Drive out to the town of Exmouth, hire a mask or take a boat, and you are among coral gardens and parrotfish within minutes. That accessibility makes the reef a rare find, a place where diving, snorkelling and wildlife encounters blend into a single, easy holiday.

From roughly March to July, the headline act is the whale shark. The reef's waters attract the world's largest fish, and licensed boats take small groups out with spotter planes to find them. The encounter is done as a snorkel, with strict rules about how close you may approach, and in a good moment you float beside an animal as long as a bus, moving slowly through the blue. Manta rays are year-round residents around Coral Bay, humpback whales pass between August and October, and the Exmouth Navy Pier, one of the world's finest shore dives, offers an endless parade of life under the old jetty for those who book with a licensed operator.

Ningaloo is not a typical dive resort. The best dives are about the animals rather than dramatic walls, and the water can range from clear to murky depending on the wind. That suits people who want a flexible, family-friendly trip with a mix of snorkelling, diving and wildlife watching. It also means the nearest recompression chamber is a long way off in Perth, so a conservative approach is wise. Pack a thin wetsuit for the cool mornings, book whale shark tours in advance in peak season and listen carefully to the briefing, because the rules protect an experience that is still among the world's most responsible wildlife encounters.

Raja Ampat means four kings in Indonesian, and the name refers to the four large islands that anchor an archipelago of more than fifteen hundred small islands, cays and shoals off the northwest tip of Indonesian Papua. Scientists who survey the reefs here keep arriving at the same conclusion: this is the centre of marine biodiversity on the planet. Hundreds of coral species, well over a thousand species of reef fish and a strange diversity of small oddities such as walking sharks and pygmy seahorses have been recorded here. To see it, you board a phinisi-style liveaboard in Sorong or stay at a homestay on the islands, and let the days merge into a loop of dives, jungle views and sunsets over limestone karsts.

At Cape Kri, divers in the current have recorded more fish species on a single dive than almost anywhere else, with trevally, snapper, barracuda and sharks passing in layers. Sardine Reef and Blue Magic offer drifts with mantas and sharks, while Misool's soft coral walls and Wayag's hidden lagoons are the reason many people come. Near Arborek, manta rays circle cleaning stations, and the village jetty is a tiny paradise of juvenile fish and shy species.

Plan around the moon. Full and new moons bring spring tides and strong currents, and divers with fewer than a hundred dives will often prefer the gentler neap tides. Visitors pay an entry fee, set at one million rupiah per person under a 2025 regency regulation, plus a separate marine park charge whose current amount your operator should confirm in writing. Recompression chambers are a long way away in Manado or Makassar, and many boats run older compressors, so carry your own Nitrox analyser. Treat the water with respect, and it will repay you with a week that no other reef can match.

Lembeh Strait is the opposite of the postcard. There are no walls, no clear blue water and no giant animals. What you get instead is a seabed of black volcanic sand, scattered with coconut husks, old tyres and sponges, where some of the most extraordinary creatures on the planet hide in plain sight. The strait runs between the mainland of North Sulawesi and Lembeh Island near the port of Bitung, and the dive sites, with names such as Nudi Falls, Hairball and Police Pier, are the world's best-known muck dives. You descend with a guide who carries a pointer and a sharp eye, and you spend an hour on a stretch of sand that looks empty to everyone but them.

Then the show begins. A mimic octopus rises from a burrow and morphs into a flatfish, a hairy frogfish waves a tiny lure from a sponge, a flamboyant cuttlefish crawls across the sand while flashing pink and purple, and a blue-ringed octopus shows its warning colours from inside a shell. Pygmy seahorses, ghost pipefish, harlequin shrimp and dozens of nudibranchs fill out the cast. It is a dive style that rewards patience, careful buoyancy and the ability to hover motionless for ten minutes while a guide helps you find something no larger than a grain of rice.

Photographers adore Lembeh, but its ethics matter. The best operators forbid touching or moving animals for a photograph and brief you on how to behave around species that are easily stressed. Visibility is lower than in the clear-water destinations, often between five and fifteen metres, and the water can be cooler than you expect, so a 3 mm suit and a hood help. The dives are shallow and the current is generally gentle, which makes Lembeh a good place for relaxed, unhurried diving, and a gateway to a branch of the hobby that many divers find more addictive than any big animal.

On 6 October 1941, German bombers found the British cargo ship SS Thistlegorm at anchor in the northern Red Sea, waiting to pass through the Suez Canal, and sent her to the bottom with a cargo that included trucks, motorcycles, rail wagons, ammunition and two locomotives on her deck. For decades she lay forgotten, until Jacques Cousteau located her in the 1950s and divers rediscovered her in the 1990s. Today she rests in roughly thirty metres of water, upright and intact enough that you can swim through her holds and see the cargo as it was loaded.

Diving the Thistlegorm is an experience of scale and surprise. You descend a mooring line into water that can be green or clear and see the long hull appear, then drop into the first hold and find rows of Bedford trucks, Norton and BSA motorcycles, wheels, rifles and boots stacked as though a quartermaster had stepped away for lunch. Outside, the ship's guns still point at the sky and the locomotives lie in the sand. Schools of glassfish and batfish drift through the beams, and groupers and lionfish hide in the shadows.

It is also a demanding dive. Currents can be strong at the mooring line, the site is busy, and the wreck's interior needs training, good buoyancy and respect for fragile structures. Most operators run the trip as a long day from Sharm El Sheikh or Hurghada, often with a two-dive plan: one to look around the outside, one to go inside. A wreck course will give you the confidence to enjoy it, but even without one, a good guide will show you the highlights. Remember that the Thistlegorm is both a historic site and a gravestone, so take photographs, not souvenirs.

The Azores sit in the middle of the Atlantic like a stepping stone between continents, nine volcanic islands that rise steeply from deep water and look as if they belong in a different, wetter, greener part of the world. Hydrangeas line the roadsides, cows graze on volcanic slopes, and the air carries the smell of the sea and wet grass. Under the surface the same volcanic drama continues in arches, caves, steep walls and pinnacles, and the surrounding deep ocean delivers visitors that reef divers rarely meet.

From June to October, divers head out to offshore seamounts such as Princess Alice Bank, where schools of mobula rays appear in the blue and, with luck, a blue shark or a manta ray glides by. The Formigas islets and the Dollabarat reef off Santa Maria are known for mantas and big schools of fish, while around Pico and Faial, volcanic caves and shipwrecks give variety for less demanding days. Mola mola, the strange ocean sunfish, appear in summer, often resting at cleaning stations, and sperm whales and dolphins cross the channel between Pico and Faial.

Because the Azores are cool, with water that ranges from the sixties to the mid-seventies Fahrenheit, you should bring a thicker wetsuit or a drysuit. Blue-water dives on seamounts can involve current and open-ocean conditions that call for Advanced certification and a surface marker. On land, the islands reward a longer trip, with hot springs, crater lakes and charming towns, so many visitors split their stay between diving days and exploring days. Combine two islands, such as São Miguel with Pico or Terceira, and you get a trip that feels like a small expedition within easy reach of Europe.

The Rowley Shoals are three coral atolls, Mermaid, Clerke and Imperieuse reefs, that rise from deep water several hundred kilometres west of Broome in Western Australia. They are so remote that for most of the year the only boats are a handful of liveaboards and the occasional research vessel. From a distance each atoll looks like a pale green oval in a dark blue sea, with breaking waves on one side and a calm lagoon inside, and the colours alone tell you why people travel here.

Below the surface, the reefs are famously clean. Visibility often exceeds thirty metres, hard corals grow in healthy tables and plates, and the lagoon bommies teem with fish. Divers describe the passes between the lagoon and the open ocean as natural aquariums, where tidal flows bring grey reef sharks, schools of trevally and Napoleon wrasse, and turtles rest in the shallows. Giant clams, some a metre across, sit in the shallows like ornate bowls, and in the right season humpback whales may pass offshore.

Because the shoals are protected by marine parks, access is through licensed operators, and the season is short, roughly September to December, when seas are calm enough for the crossing. A multi-day liveaboard out of Broome is the usual way to go, and the cost, combined with flights to the Kimberley, places this destination at the top end of the budget range. The nearest recompression chamber is far away in Perth, so a conservative profile and a good emergency plan are essential. If you want a reef that feels as if it belongs to nobody, this one comes as close as any in Australia.

Triton Bay is what Raja Ampat felt like before the crowds arrived. On the southwestern coast of West Papua, near the small town of Kaimana, the bay is a sheltered maze of limestone islands, karst cliffs and mangrove inlets, with water that is often green with plankton and a coastline that shows no sign of resorts or roads. You reach it via a connecting flight to Kaimana and then by liveaboard or small boat, and the journey feels like a small act of exploration.

The diving is a surprise. Where you might expect big animals, you find shallow reefs draped in soft corals, with colours so vivid and so dense that they look painted. Macro life is plentiful, and some sites have remarkable fish schools. The bay is also known for its whale sharks, which gather around local fishing platforms called bagan, where fishermen net small fish at night and the sharks hover beneath the lights to feed on scraps. The animals are often seen, but they are also an example of the difficult ethics of wildlife tourism.

Interactions near the bagan are a form of provisioning, because the sharks come for the fishermen's catch, not because of a natural aggregation. Choose operators who observe the sharks without touching them, keep boats at a respectful distance and avoid feeding. Visibility is usually modest and the water is warm. Because the infrastructure is thin, trips need planning: liveaboards are limited, medical help is far away, and there are no shortcuts. Divers who come are rewarded with soft coral gardens, quiet sites and a sense of being among the first to arrive.

Zanzibar's reputation is as a spice island of white beaches and carved wooden doors, and diving is a pleasant addition rather than the main event. Land in Stone Town, wander the narrow alleys where traders once sold cloves and cinnamon, and cross the island to the northeast coast where the water turns a spectacular turquoise. This is the gateway to Mnemba Atoll, a small, protected island ringed by coral and surrounded by blue water that has been a marine conservation area for years.

Mnemba is the best-known dive area, with sites such as Kichwani Wall, the Aquarium and Big Wall, where hard and soft corals cover the slopes and schools of fish shimmer in the current. Green turtles are common, lionfish hover in the shade, and dolphins sometimes accompany the boats on the way. Do not expect big sharks, because this is not a pelagic destination; instead, you get a gentle, colourful and often relaxed set of dives that suit beginners and intermediate divers and blend easily with a beach holiday. Far to the north, the island of Pemba offers steeper walls and stronger currents for those who want more challenge.

The best season is June to October, when the weather is dry and cooler and the sea is calm, but December to March is also good if you can bear the heat. Dolphin tours at Kizimkazi are a popular add-on, though crowded boats chasing the animals are a concern, so choose an operator that follows a code of conduct and limits the time spent with each pod. Diving here is generally easy and affordable, but the medical infrastructure is limited, so ask your operator about emergency procedures, and bring reef-safe sunscreen, because the beaches are fragile too.

South Africa is wild diving at its most rewarding. The country's eastern coast, between Durban and the Mozambique border, is washed by the warm Agulhas Current, which brings tropical reefs and a startling quantity of sharks. Diving here begins on the beach, where boats are launched through the surf by tractors or skilled skippers, and you hold on tightly as the vessel crashes over the waves. By the time you reach the dive site you have already had an adventure, and the sea is just beginning to show what it has.

At Aliwal Shoal, off Umkomaas, a long reef and several wrecks attract ragged-tooth sharks, also known as sand tigers, which gather in numbers between May and October. They look fearsome with their jagged teeth but are usually gentle, and watching them cruise the gullies at Cathedral is a highlight. Tiger sharks and Zambezi sharks also visit, and the reef is covered in soft corals and fish. Farther north, Sodwana Bay in the iSimangaliso Wetland Park offers Two-Mile Reef and Seven Mile Reef, where turtles, moray eels, blacktip reef sharks and schools of fish live among healthy hard corals.

Plan the season carefully. The winter months of June to October bring clear water, shark activity and migrating humpback whales, and the legendary Sardine Run, when millions of sardines move up the coast with dolphins, sharks and gannets in pursuit, is mostly a surface spectacle that unfolds unpredictably between June and July. Many operators offer shark dives, and some use bait, so ask how the encounters are organised and choose responsibly. The water is cooler than in the tropics, so a thicker wetsuit is a good idea, and surf launches mean a dry bag for your camera is essential. South Africa gives you a big, varied and affordable slice of the ocean.

The Farne Islands are the last place most divers expect to fall in love with the sea. Lying a few kilometres off the Northumberland coast in the North Sea, they are known for puffins, Arctic terns and the lighthouse on Longstone, from which Grace Darling and her father rowed out in 1838 to rescue survivors of a shipwreck. You board a dive boat at Seahouses, ride past rocky islets where seabirds clamour and slip over the side into water that is cold, green and surprisingly alive.

The stars of the show are the Atlantic grey seals, which breed on the islands in large colonies. Underwater, they are curious, playful and sometimes mischievous, swooping around divers, tugging at fins and gazing into masks with enormous dark eyes. They often seem to enjoy human company, and an hour spent with a bold pup is hard to forget. Beyond the seals, the sea floor is covered in kelp forests, anemones and starfish, and old wrecks lie among the rocky reefs, each covered in life.

Cold-water diving requires specific preparation. Temperatures range from about seven to fifteen degrees Celsius, so a drysuit and the training to use it properly make the difference between a miserable day and a fantastic one. Visibility can be modest, often between five and fifteen metres, and tidal streams are strong enough that operators schedule dives around slack water. The best season is from May to September, while the autumn seal pupping season may restrict access to some islands. The islands are protected nature reserves, so follow the rules of the licensed boats. For divers used to tropical water, this is a refreshing reminder that some of the best encounters are on your doorstep.

The Banda Islands once made Europe go to war. In the seventeenth century, this tiny cluster of volcanic islands in eastern Indonesia was the only place on Earth where nutmeg grew, and the spice was worth more than gold. The Dutch and English fought over it, and in 1667 the Treaty of Breda saw the English give up their claim to the island of Run in exchange for a small colony on the other side of the world called New Amsterdam, later renamed New York. Today the islands are quiet, with colonial forts, spice gardens and a volcano called Gunung Api that rises above the harbour.

Beneath the surface, the Banda Sea is just as dramatic. Steep volcanic walls plunge into deep blue water, and healthy coral reefs thrive in the nutrient-rich currents that sweep through the archipelago. The lava flow site at Gunung Api, where black rock from the 1988 eruption has been colonised by coral, is a fascinating dive, and the surrounding walls are packed with fish. Schools of hammerheads are reported at some Banda Sea seamounts in season, and the same currents bring tuna, jacks and turtles. To the south, the Alor Archipelago offers some of the most dramatic pass diving in Indonesia, with strong currents funnelling between islands and carrying pelagic fish past reefs that remain among the healthiest in the country.

Getting here takes effort. You fly to Ambon, then take a small plane or a boat to Banda Neira, or join a liveaboard that loops through the Banda Sea. The season is short, with the calmest conditions generally falling between September and December, and the currents can be strong enough to demand Advanced certification and a surface marker. Medical help is far away, so travel insurance with evacuation cover is essential. For divers who have already seen the famous spots and want a place where the ocean feels untouched and the history is as intriguing as the diving, this is one of Indonesia's best-kept secrets.

Most atolls in the Maldives are rings of coral around a lagoon. Fuvahmulah is different. It is a single, oval island in the far south, sitting alone on a steep underwater mountain with no lagoon at all, and it feels like a small green dot lost in the equatorial Indian Ocean. You reach it by a domestic flight from Malé, drop your bags at a local guesthouse and wander a place where freshwater lakes lie inland and the sea thunders against the shore. The island is a long way from the busy resort atolls, and it seems to belong to a different world.

The diving is some of the most exciting in the Indian Ocean. Because the island rises directly from deep water, it attracts large oceanic animals that are rare elsewhere. Tiger sharks are resident and regularly seen at the site known as Tiger Zoo, sometimes in numbers that look unreal. Thresher sharks come up from the deep to be cleaned on the reefs, oceanic manta rays pass by, and hammerhead and silky sharks cruise the blue. Currents are strong and the swell can be large, so dives are often drifts or negative entries, and you must be confident in the water.

Ask how the encounters work. Some sites may attract sharks with bait or provisioning, and practices vary between operators, so choose one that follows clear safety and ethical guidelines and does not feed animals in a way that changes their behaviour. The best season for threshers and for calm seas is generally the dry months from December to April, though tiger sharks are seen all year. Medical help is limited and the chambers around Malé are a flight away, so insurance and conservative profiles matter. If you are an experienced diver who wants big animals without a long liveaboard crossing, Fuvahmulah is one of the most rewarding places in the Maldives.

Saba is the kind of island that makes you laugh on arrival. You fly from St. Maarten in a small plane over a short stretch of sea, the island rises like a green cone, and the pilot lands on one of the shortest commercial runways in the world, a strip of tarmac that ends at a cliff. It is a five-square-mile volcano with a single road, steep staircases and tiny villages whose white houses with red roofs cling to the slopes, and it feels as if the island has been frozen in time.

Underwater, the volcano continues, with pinnacles rising from deep water to within a few metres of the surface. Saba Marine Park, created in the 1980s, protects the island's reefs, and the result is a collection of healthy coral and sponge formations at sites such as Third Encounter, Outer Limits and Diamond Rock. Fish life is abundant, with schools of creole wrasse, Caribbean reef sharks cruising the edges and turtles on the reefs. The park uses permanent moorings, so anchors never touch the coral, and dive groups are small. A short hop to the neighbouring island of St. Eustatius, known as Statia, adds historic wrecks such as the Charles L. Brown and the remains of a once-bustling colonial harbour on the sea floor.

Divers who know the Caribbean describe Saba and Statia as the quiet alternative to busier islands. There are no big resorts, no cruise ships and few dive boats, and the diving is relaxed and often free of crowds, even in peak season. Costs are moderate, but travel takes planning, as flights from St. Maarten are limited and weather can delay them. Strong currents are rare, so these sites suit intermediate divers. Because the islands are small, check the location of the nearest recompression chamber and confirm your evacuation plan with the operator, and consider extra days for hiking up Mount Scenery.

India's coastline has quietly become a credible place to learn and enjoy scuba diving, and the best way to understand it is to think of the country as several small dive regions rather than one. In the Andaman and Nicobar Islands, Havelock's Elephant Beach and Corruption Rock offer the warm water and healthy reefs that draw most travellers, and the dive season runs from roughly October to April. On the other side of the subcontinent, Lakshadweep's Kadmat Island, best between November and March, delivers turtles and live coral, while the coastal waters of Pondicherry, where operators visit sites such as Temple Reef and Four Corners, give urban visitors a surprisingly accessible introduction to the sport.

Farther along the west coast, Netrani Island off Karnataka, an uninhabited rock about ten nautical miles from the mainland, has coral reefs and the possibility of seasonal whale sightings, although diving there is generally possible only for a short window in December and January. Kovalam, near Thiruvananthapuram, is a beach town where snorkelling and shallow dives are offered from early September to February, while Tarkarli in Maharashtra, a few hours from Mumbai, combines clear turquoise water with coastal scenery. Prices quoted in our earlier guides, roughly five and a half thousand to seven thousand rupees per dive in 2020, will have moved, so ask operators for current rates.

If you would rather stay near the surface, snorkelling in India is gentler and cheaper, with calm bays and gear for hire at beachfront centres. Our guide to the best places for snorkeling in India covers Kovalam, the Andaman Islands, Netrani, Lakshadweep and Tarkarli in detail, and our longer guide to the best places to scuba dive in India lists dive sites, seasons and approximate costs. Whichever path you choose, pick operators with trained instructors, check that the gear is serviced and never dive beyond your certification, however easy the water looks.

Every dive guide tells you where the manta rays are. Far fewer tell you what happens at three in the morning when a diver on a remote liveaboard feels unwell, or why the same reef can look like a postcard in March and like green soup in August. This chapter collects the operational realities that experienced divers ask about first: the medical distance, the moon, the gas in your tank and the small mismatches that quietly ruin expensive trips. None of it is glamorous, and all of it is the difference between a good story and a bad one.