At first, the ocean seems empty. Through my snorkelling mask I see only a deep blue nothingness. Then suddenly they are there; dark, lithe shapes gliding in perfect formation like aerobatic pilots.

The spinner dolphins seem oblivious to my presence, cavorting around me for the fun of it. They come here every morning, dozens of them, to a sheltered lagoon framed by jagged mountains off the coast of Mauritius, to rest and play in tranquil water.

"An encounter with nature in one of her most enchanting guises" Credit: Getty

Swimming among them is an encounter with nature in one of her most enchanting guises. They are like smiling torpedoes, cruising with effortless power and grace in an endless realm.

I just wish they didn’t swim so fast. Even with fins on I keep pace for barely half a minute before their tails flip farewell, and they are gone.

We are lucky. We came early when there were only a couple of other boats of dolphin chasers. By the time we leave, the bay is crowded with dozens of boats and people thrashing about in pursuit of flashing flanks. The best plan is to come early, like the dolphins.

Colonel C G Gordon of the Royal Engineers (later General Gordon of Khartoum) would have been amazed by such activities. In 1881, clearly bored with a Mauritius posting, he wrote to Sir Charles Elphinstone: “If you want to find a place where things have been let go to sleep, I recommend you to try Mauritius.”

As the island celebrates the 50th anniversary of independence from British rule this year, its allure as an Indian Ocean haven of rest and recuperation is undiminished. According to the last count, more than 100,000 Britons head for its beach resorts every year, and spend much of their time contemplating a tranquil sea and blue skies.

For those prepared to forsake their sun loungers, however, Mauritius has more to offer than Gordon could have dreamed of. Apart from close encounters with dolphins, the island’s bid to broaden its anniversary appeal under a tourism slogan “Beyond the beach” features hiking in indigenous forests that are a refuge of rare bird life, undersea adventures à la Jules Verne, and time travel in grand colonial piles and quirky museums.

Alexandra Falls, Black River Gorges National Park Credit: Getty

My discovery trail with a driver provided by the tourist board begins on a mountain road in the less developed south of the island, rising to a viewpoint over the Black River Gorges National Park. This is a wild expanse of thick forest, the last vestige of native flora and fauna decimated over generations by human settlers.

The little that remains, thanks to determined conservation efforts, is magnificent. It is a vision of the dawn of time, a tumult of mountains swathed in tropical woodland presided over by the island’s highest summit, and scarred by deep river gorges plunging to the sea.

White tropicbirds with long, graceful tails drift silently below and a chorus of chirruping and twittering echoes around sheer rock faces. In the far distance the serrated peaks of dark mountains brood beneath a lowering sky over coastal plains and a ghostly grey sea. A distant rumble of thunder heightens the drama of a primal landscape seemingly untouched by humankind.

As I stand wondering at the prospect, two extravagantly plumed birds alight on a nearby branch and proceed to serenade each other with sweet warbling. They fly off when a couple of macaque monkeys amble along the parapet.

Macaques in the Black River Gorges National Park Credit: Getty

A few days later I am in the forest with a guide, an ultra-distance runner who used to be a Cistercian monk in Haute-Savoie, France. Yan is the kind of man who doesn’t climb mountains, he bounds up them while discoursing eloquently on nourishing the soul through nature.

As we climb a pilgrims’ trail towards a sacred Hindu lake, he explains how the park is reverting to its natural state through the eradication of invasive species such as guava and gum trees, and their replacement with native ebony. In the process, the natural habitat of endangered bird life is being restored.

The late lamented dodo, flightless clown of the bird world, was shot and devoured to extinction by 17th-century Dutch sailors. More recently the Mauritius kestrel was the world’s rarest bird when only four could be found, and the echo parakeet was faring little better on the critically endangered list, numbering only 15, but now hundreds of them are flying around Black River forests. They prove elusive on our hike, but the air is filled with the screeching of fruit bats. “I call it the dance of the bats,” Yan says. “When they circle in the air it is beautiful.”

Descending from a rock ledge viewpoint, we are invited to swim in a succession of rock pools fed by the cleanest, freshest river on the island. It is, as Yan promised, good for the soul.

He also leads hikes up a nearby Unesco World Heritage site called Le Morne, a great, glowering watchdog of a mountain brooding over the sea that is a monument to despair and defiance. In the early 19th century it became a refuge for runaway slaves, and in February 1835 hundreds threw themselves from the summit to their deaths when they saw police approaching, presumably to arrest them. In fact the police had come to tell them that slavery had been abolished, and they were free. It is a place that by its very nature seems unable to banish the torment of the past.

Being prone to vertigo I decline an offer to climb it, and dive instead to 20,000 leagues under the sea with Captain Nemo. Actually we descend to a more modest 115ft to a seabed shipwreck in a mini-submarine with Captain Samuel – but to a lively imagination, the experience is much the same.

The 10-seater vessel is the brainchild of Luc Billard, a round-the-world yachtsman who’d had enough of life on the ocean waves and decided to explore beneath them. It is one of only a dozen “leisure” submarines in the world, certified by its Finnish constructors to a depth of 260ft.

The interior is a miniature Nautilus, with portholes and a big fish-eye window in the bow. As we descend we are investigated by angelfish gazing curiously at us, and a sea turtle swims lazily by as if flying.

Drifting slowly over rocks and coral, we are imbued with a profound sense of peace and calm, deepened by a soundtrack of ethereal music. It is like being in a dream.

Then a ghostly shipwreck appears, a Japanese trawler sunk a few years before to create an artificial reef. In the absence of monstrous Nautilus-eating squid, shoals of clown fish and blue striped snappers swarm around us when our captain releases breadcrumbs, and we are enveloped in a swirling rainbow of fish.

For a more exclusive experience, Luc has a five-seater submarine for champagne lunches, and weddings with just enough room for the happy couple, a civic official and two witnesses. The flotilla is completed with scooters that cruise underwater at 10ft. “You can touch the little fish, it’s a different experience,” he says.

Back on land, I eventually spot a Mauritian kestrel and a pair of echo parakeets, along with scarlet ibis, blue-and-yellow macaw and African crowned crane, in a dazzling array of high-fliers in an enormous walk-through aviary. The bird sanctuary is at the heart of Casela World of Adventures, an open-air zoo and adventure playground where visitors are encouraged to get close to the animals, including tame lions.

The island's southern tea plantations Credit: Getty

After all this excitement it is time for tea, and Le Bois Chéri plantation is the place to savour the finest blends the island has to offer. A rustic wooden chalet restaurant on a hilltop overlooking a forest lake has a tasting room where visitors can sample teas infused with vanilla, caramel, exotic fruits, cardamom and coconut. Manager Yan-Claude Masson explains that the character of tea depends on the altitude of the estate. The higher the plants, the stronger the brew – and at only 1,600ft, Le Bois Chéri produces light, fragrant varieties.

After lunch, guests can avail themselves of free kayaks and pedalos on the lake, and admire its resident population of black swans. Should they wish to stay the night, there is a futuristic inflatable “bubble lodge” with all mod cons by the water’s edge to enjoy the evening tranquillity of woods and water.

A sense of history lingers in colonial architecture, hilltop citadels, and on the shelves of Monsieur Célestin Harel’s little shop La Pirogue in the village of Curepipe. He and his family create exquisite scale models of famous ships, and his shop is a voyage into maritime history with diversions into fantasy, from Nelson’s Victory and Bligh’s Bounty to Jack Sparrow’s Black Pearl. I gaze in boyish wonder at the Unicorn, sailing from the pages of a Tintin adventure.

On bidding farewell to my driver, I am assured that after half a century Mauritians bear no ill will towards former colonial rulers. “We don’t have bad memories of colonialism,” he says, “except for the Dutch because they ate all the dodos.”

Essentials

Where to stay

Paradise Cove is an adults-only boutique hotel in a romantic setting with first-class facilities and fine dining. Seven nights half-board in a Deluxe Room costs from £1,735pp including return flights from London, booked through Kuoni (01306 747008; kuoni.co.uk).

For families, the Ravenala Attitude hotel combines good-quality accommodation and cuisine with land and water sports for youngsters. Seven nights all-inclusive in a Couple Suite costs from £1,635pp with return flights from London, also available through Kuoni.

Need to know

People An ethnic cocktail of Africans, Indians and Chinese in mainly social and religious harmony.

Language An imbroglio of English, French, Creole and Hindi; English is widely understood.

Currency Mauritian rupee, worth about 45 to the pound.

Seven Coloured Earths Credit: Getty

Climate Summer (from November to April) is hot and humid, with the cyclone season from January to March. Winter (May to October) is cooler/drier.

Health There are mosquitos but no malaria, and reasonable medical services.

Getting around

The easiest way to see the sights is on local tours that arrange excursions and activities with multilingual guides.