I found the most surprising way to experience India's beating heart

A group of young men are standing atop a timber public ferry with faded blue trim, sides worn smooth by the tides. The boys laugh and wave from the bow of the wooden boat before taking their turn leaping into the milky brown river Hooghly (or Lower Ganges).

Nearby, a woman in a crimson sari standing on the ghat's bottom step cups her hands to lift the sacred river's water to her forehead. A saffron-robed sadhu also wades into the water seemingly oblivious to the Ganges Explorer II as it drifts slowly by.

"To embrace India in its entirety, to discover its beating heart, you simply must travel along its river," says Raj Singh, trailblazing owner of Ganges Voyager I and Ganges Voyager II, who charters the boats to Uniworld Boutique River Cruises.

Singh established his first river cruise in India in 2009. And the entrepreneur says he's very proud to continue the tradition of celebrating Ganga Ma (Mother Ganges) with Uniworld.

"My background is in hotels and hospitality. But I grew up around the rivers. These two experiences led me to dream of a journey that combined luxury with the rich heritage of India's waterways," he says.

"We are a luxury brand, but we're also intent on preserving the waters and wildlife and travel with purpose so that we benefit the communities who live along the rivers," he says. All ships are plastic-free and built, designed and run by Indians - a sustainability ethos that aligns with Uniworld's Make Travel Matter experiences aimed at advancing United Nations Global Goals.

I boarded the Ganges Voyager II in Kolkata in the state of Bengal, where Uniworld River Cruises offers a seven-day sailing out of Kolkata. It's part of an extended 13-day Golden Triangle & the Sacred Ganges package, which includes a land leg travelling by coach around India's Golden Triangle - Delhi, Agra and Jaipur - with stays in the luxury Oberoi Hotels.

But our first taste of India is not aboard a serene riverboat. Rather it's an adrenalin-fuelled cycle rickshaw ride through Old Delhi's narrow alleyways, manoeuvring around cyclists, pushcarts and people. It's Raiders of the Lost Ark with a Bollywood soundtrack. Women shuffle along in saris. Stallholders shout out their prices. And snatches of music blare as we negotiate Chandni Chowk's crowded lanes crammed with stalls selling everything from saris to stationery.

After the sensory overload of the Golden Triangle's magnificent palaces, markets and monuments, boarding the luxury riverboat, which cruises from Kolkata as far north as Baranagar, feels like stepping into another world.

My tranquil suite - with intricate hand-painted murals, a four-poster bed, carved armchairs and marble bathroom - becomes a quiet haven for contemplation. The boat, purpose-built by Singh to ply the waters of the Ganges, carries a maximum of 56 passengers attended by 36 staff, some who've worked with him for decades.

Bikash (Vikas) Mehra is one of them. "My DNA is Punjabi, but my soul is Bengali. I look forward to showing you the rich heritage of my home state," says Vikas, one of three onboard guides steering small groups of passengers ashore to visit sites of historic and cultural significance.

In Kalna, the "Temple City", Uniworld's immersive onshore excursions include a rickshaw ride to the enchanting Naba Kailash, built in 1809, featuring 108 shrines dedicated to Hindu deity Lord Shiva.

Vikas also leads us through a local market full of bustle, colour and noise before venturing to Chandernagore's colonial promenade. The former trading post, established as a French colony in 1673, flip-flopped between French and British rule until 1950, three years after India got its independence.

"The French left a unique imprint in Chandernagore and that blend of French and Indian culture is something you can still see today in the tree-lined boulevards, pastel villas and heritage architecture," Vikas explains. Back in Kolkata, an excursion to the flower market below Howrah Bridge, which bracelets the river Ganges, is a feast for the senses.

Here we find hanging strings of marigolds and stallholders striding past wearing bales of flowers on their heads like colourful up-dos. Equally memorable is a visit to the traditional potter's village of Kumartuli, in northern Kolkata, where we find craftsmen bending bamboo to form deities and sculptures in various stages of undress, clad only in straw and clay.

Beyond the excursions, there are epic feasts, cooking workshops, yin yoga classes and cultural performances led by local Bengali Baul singers who board the boat along the way. There's also a visit to the local NGO Calcutta Rescue, which provides free education to underprivileged children and is part of Uniworld's Make Travel Matter program.

The more time spent travelling along the river, the sharper the image of India becomes. It's like a Polaroid starting to develop. As we sailed from Kolkata, the handcrafted vessel, with its dark timber detailing and luxurious amenities, transforms what would have been a gruelling overland journey to out-of-the-way Kalna an effortless breeze.

There is, says Singh, no other mode of travel quite like it in India. Days spent gliding on the Ganges are well spent. Everything is all-inclusive, from the complimentary beverages to the excellent meals, and cocktails and canapes at dusk in the lounge bar. The sun deck is also perfect for reclining on rattan plantation chairs covered in fabrics that mirror the copper sunsets and textures of the landscape.

But to truly embrace India, you can't just travel by boat. Starting the Golden Triangle & the Sacred Ganges itinerary with consecutive stays at three luxe Oberoi properties was like the Act One of India. And the contrasting elements of each property reflect the complex nature of the country's past, present and future - from the modern silhouette of The Oberoi, New Delhi, which gives visitors a taste of contemporary India, to The Oberoi Amarvilas, Agra, where bedroom windows frame the grandeur of the Taj Mahal, to The Oberoi Rajvilas, Jaipur, where some 150 peacocks strut around the blushing pink buildings designed to resemble a palace fit for a maharaja.

The land-based portion of the trip also includes jaunts to Jaipur's City Palace, still run by royalty, and the Jantar Mantar, a UNESCO World Heritage Site featuring massive stone instruments built between 1728 and 1734 as well as the world's largest stone sundial.

While visiting India's temples and grand landmarks such as the Taj Mahal, Amber Fort and the pink city of Jaipur by coach is as wonderful as it was when I first visited the Subcontinent two decades ago, it's observing the gentle rhythm of life unfolding along the riverbank that proves most transformative. Between the ports and palaces, we meet sari-clad women who pause to pose for photos. Stallholders who wave us over to taste a piece of fresh mango. And children who lean into our lenses with friendly smiles.

Celebrating both the historical significance and mystique of the 2500-kilometre-long river that threads through the landscape from its headwaters in the Himalayas all the way to the Bay of Bengal is something Uniworld does exceptionally well. At dusk on the final day of the voyage, I sit on the top deck watching the river absorb the colour of the sky, as the ship is lit in apricot hues.

There are women filling buckets by the water's edge. Men fishing from small dinghies. Children tending to goats. And others yahooing into the river. It's like piecing together an intricate jigsaw of India.

After the curtain comes down on the final act - a cultural performance presented by local Kolkata dancers - I am joined by Vikas staring up at the waning moon. Before we bid each other farewell, I ask Vikas if the music I can hear tumbling over the brown river near Chandernagore is coming from a festival. "No," he deadpans. "That is just India being India."

The writer was a guest of Uniworld Boutique River Cruises