While in many destinations, whale sharks only pass through for a couple of months each year Tofo Beach, Mozambique, sees these enormous animals year-round. Much conservation work is being done to ensure this remains the case—marine conservation NGO the Marine Megafauna Foundation recorded a 79 percent decline in whale shark sightings in Mozambique between 2005 and 2011, which is a hugely worrying trend. For the best chance of seeing a shark, join an “ocean safari” with a dive operator like Peri-Peri Divers where you’ll zig-zag around the bay looking for marine life to swim with. If you’re lucky, you might spot manta rays, dolphins, turtles, or humpback whales (from June to October) on the boat trip too.

When to visit: Year-round

Mafia Island in Tanzania is rich in plankton which draws in a strong resident population of whale sharks. With fewer tourists and a selection of small, locally-run tour operators, it’s a potentially underrated destination for travelers as well as an interesting site for conservation scientists. To make sure these gentle giants are protected, researchers—such as whale shark expert Dr. Simon J. Pierce—are conducting studies in the area, Tanzanian NGO Sea Sense has delivered training sessions on sustainable tourism, and the Tanzania Fisheries Research Institute is working to reduce the instances of sharks getting entangled in fishing nets.

When to visit: November to December

A recent study by the Madagascar Whale Shark Project (MWSP) revealed that Nosy Be, Madagascar, is a feeding hotspot for juveniles. The sharks—like Michel who has been seen more than 35 times since MWSP researchers arrived in 2015—spend lots of time here and often return year after year. You can also see the impressive spectacle of the sharks vertically feeding (somehow, an eight-meter shark towering next to you feels much bigger than one swimming horizontally).

With increased global awareness of Madagascar’s whale sharks, the team behind the study has also implemented a code of conduct across the island. These carefully developed guidelines ensure the best interests of the animals remain at the heart of all encounters—so, if you do visit, please book with an operator like Baleines Rand’eau who uses the code. As well as protecting the animals, you’ll have a better, uncrowded encounter.

When to visit: September to December

Home to many weird and wonderful creatures seen nowhere else in the world, it probably comes as no surprise that the Galapagos is also particularly special when it comes to whale sharks. This is because it’s the only place in the world pregnant females are regularly seen.

Why do pregnant females come to the Galapagos? Do they give birth here? Where do the mothers and babies go once they’re born? Put simply, scientists don’t really know. Whale shark reproduction is a bit of a mystery actually: no-one has ever seen a whale shark give birth and only one pregnant shark has ever been examined.

When to visit: June to October

The Philippines is home to the world’s third largest population of whale sharks, according to global database WhaleShark.org. A recent satellite tagging study by LAMAVE, which tracked a number of sharks and found none left the archipelago, confirmed the importance of this destination for these endangered creatures.

In terms of visiting as a tourist, Southern Leyte and Tubbataha are the best areas to aim for. Being totally frank, it’s best to avoid the most-publicized (and overcrowded) site, Oslob, because operators feed the sharks to maximize sightings. This can be problematic because sharks that rely on humans can change their migration patterns—hanging around the same area for a reliable source of food—and risk malnourishment from a poor diet. Choose your destination and operator wisely. Let’s face it, those who prioritize profits over the wellbeing of the animals, aren’t going to care whether you have an enjoyable and safe encounter either.

When to visit: February to April

The summer is spawning season for little tunny—a small species of tuna—in the waters just north of Isla Mujeres on the Yucatan Peninsula in Mexico. The fish produce millions of eggs which, in turn, bring huge numbers of whale sharks flocking to the area. It’s the world’s largest known whale shark aggregation with hundreds of sharks munching on fish eggs. This means marine tourists (who, of course, flock there too for the phenomenon) have a good chance of consistent sightings—probably the best in the northern hemisphere at this time of year.

When to visit: July to August

Like the Galapagos Islands, St. Helena is one of the few places in the world where many of the whale sharks seen are adults. From genetic studies, researchers know that whale sharks are split into two main subpopulations: those across Indo-Pacific regions and those in the north-west Atlantic. St. Helena—a remote volcanic island in the mid-Atlantic—is located right in the middle of these two populations. Researchers from the Marine Megafauna Foundation are using genetic analysis to find out where these sharks come from, how different populations are connected to each other, and how they move around the world. The findings will be used to inform global conservation strategies for the species. Whale shark tours can be booked through a variety of local operators—again, ensure you book with someone who adheres to responsible codes of conduct.

When to visit: January to February

The Maldives is more of a tricky one because, yes, you can see whale sharks there and, yes, lots of people do swim with them. However, due to the number of tourists wanting to get in the water with these massive fish, it can be overcrowded. So you’ll probably have a high chance of your whale shark selfie being photobombed by someone else’s fins. There’s also the risk of injury (to yourself or one of the sharks). If you aren’t 100 percent sure you’ll be booking with a responsible operator here, it’s probably best to go somewhere else.

When to visit: May to December

Ningaloo Marine Park is a World Heritage-listed site in Western Australia with a 260-kilometer coral reef. The annual whale shark migration usually begins around February with sharks then starting to arrive at Ningaloo soon after. As well as snorkeling and scuba diving tours, some operators offer microlight trips where you can soar over these ocean giants, admiring their immense size from above. If you’re after a touch of luxury, it’s possible to book an overnight catamaran stay which includes a sunset sail, fresh seafood dinner, and an evening of stargazing as well as the opportunity to swim with the sharks.

When to visit: March to July

Djibouti—where smaller juvenile males tend to be found—is one of the lesser known destinations where you can snorkel and scuba dive with whale sharks. Make the most of the limited numbers of tourists to enjoy a more exclusive experience without the crowds. While there are day boats available, the liveaboards are a better option for a more ethical experience.

When to visit: November to February