Swimming alongside whale sharks is one of the top bucket-list experiences. Luckily there are a few destinations around the world where in-season sightings of whale sharks are almost guaranteed.

Seeing these gentle giants in the wild is an unforgettable experience, but it's essential to do so responsibly.

Keep a respectful distance at all times, choose only reputable dive operators (who limit numbers and don't entice the fish with food) and avoid flash photography. Remember, you're there to observe.

Isla Holbox is a 25-minute boat ride off mainland Mexico. As Quintana Roo’s sleepy northernmost island, it is the antithesis of crazy Cancun, which is 150km to the south.

When to go: tours depart daily from late May to September, when the whale sharks arrive to feed and mate. July to August is peak season.

Where to stay: some tour companies offer speedboat pick-up from Cancun and Playa del Carmen, but relaxed Holbox is a great alternative to the main tourist centres.

Lodging ranges from cheap hostels (try Tribu Hostel) to mid-range guesthouses (Holbox Apartments and Suites) and a smattering of plush hotels.

Operators: Willy’s (holboxwhalesharktours.net) is among the most reputable.

When whale sharks were ‘discovered’ at this fishing village, it became a top destination. Whale shark tourism is reportedly more ethical here than in Oslob, Cebu (where the sharks are fed).

When to go: whale sharks generally arrive between November and June, with sightings peaking from February to April.

Where to stay: surprisingly, Donsol is still a sleepy town with a handful of places to stay. Try Elysia Beach Resort or Dancalan Beach Resort.

Operators: Donsol EcoTour and Whale Shark Adventure and Tours both offer single day tours and multi-day packages.

Tofo is a traveller’s haven – and scuba diver's dream – 400km north of the capital Maputo. It's home to one of the largest concentrations of whale sharks in Africa.

When to go: sightings of 50-strong congregations are not uncommon from October to March.

Where to stay: choose from backpacker lodges to more comfortable B&Bs such as Baia Sonambula Guest House.

Operators: dive centres, including Tofo Scuba and Diversity Scuba, organise daily snorkelling trips in season.