Every year, the mighty Mekong River floods two-thirds of the delta, dumping rich sediment that provides three crops of rice a year. Now the farmers are burning rice stalks in the fields, smoke curling up like incense in a temple. Women fry banana fritters by the roadside, and truck drivers lie in cafe hammocks as they slurp iced coffee. It is the start of a passing parade of village people that, over the next week of my Mekong cruise, provides sticky-beaking opportunities, and the chance to meet, greet and interact in ways that seldom arise on river cruises in Europe.

We have been two days in Ho Chi Minh City at the start of our Travelmarvel river cruise, but now we are about to embark on our ship, and the real adventure begins. We board the La Marguerite at My Tho, where the Mekong is wide and coffee-brown. For the most part, the river banks are green and flat, the towns set back from flooding. Spectacle is provided not by landscapes but a ragged navy of boats, some so dilapidated they barely float. Up on their decks, families slurp noodles and brush their teeth. Their hellos carry across the water as dusk descends.

Next morning, our ship is in Cai Be, one of several Vietnamese trading towns along the river. We clamber into smaller boats and head ashore through the floating market. Locals both live and making their living on wooden boats, selling goods advertised by samples dangling overhead on long wooden poles. Some grin at us through missing teeth on the way past, but, for the most part, we are ignored as traders go about their business.

After stopping by the French-era church, our guide, Tang, leads us along a riverside street for our first true encounter with small-town Vietnam. We pass a computer shop, a workshop producing plaster spirit houses, a bonsai shop where mini-landscapes are decorated with porcelain pagodas and twisted trees. Tang says the adjacent internet cafe is supposed to provide educational opportunities – 30 per cent of Vietnamese now use computers – but it seems more the refuge of school-wagging, video-playing kids.

Cai Be is just an ordinary town. It has no remarkable sights and none of the tourist intrusions of the Vietnam coast, but it offers a glimpse into daily life, enlivened by the observations of our guide. Passing a furniture shop, Tang wags his head and sighs at the abundance of mahogany. Felling mahogany is illegal, and this is just another instance of widespread government corruption, he claims.

Further along the road is the three-storey mansion of a fish-sauce manufacturer. "It's quite a house but, you see, his factory is just across the street, so he has to live with the smell."

Tang takes us into a backyard sweet factory, which smells deliciously of coconut and melted caramel. Here, girls work eight hours a day for $5, twisting little squares of toffee into plastic wrappings. Rice and noodles are popped in giant woks and smothered in melted sugar. The heat is blistering and there's no disguising the poverty. Single chickens lurk in cages, the dirt floor undulates, and the monotony of the tasks is relentless.

Next day in Sa Dec there's another window on to local life at the riverside market. Strange tropical fruits sit in pyramids of colour, fish are descaled in buckets of water, frogs twitch in net bags. The street is crammed with motorbikes and women with panniers of goods across their shoulders. But the Vietnamese are good-natured people, and never seem to get impatient with the tour group that stands gawking in their way. Old women selling lumpy vegetables chuckle in bemusement at our interest, and pose for photos.

North along the river at Tan Chau, just short of the Cambodian border, we visit a riverside village of wooden stilt houses, surrounded by a shimmer of rice fields. Children follow us down the street, showing off by jumping from a bridge into the water. We see a house with an eel farm in its backyard, and a little temple that holds the tomb of a revered monk: a sleepy place of tiles, incense and plastic flowers. In the courtyard, an old man sits slurping tea and smiles at me through bare gums. He offers me a thimbleful of tea and I smile back, a moment of communication amid a clash of cultures.

Later, we take to cycle-rickshaws and visit mat-weaving and silk-weaving factories. We can give something back to the community here by buying silk clothes and tablemats. We are discouraged from handing out money, especially to children. "Unfortunately, that becomes a source of family income and then the kids are taken out of school and essentially become beggars," our guide explains. "But you may give them pens and notebooks."

Over the next two days,  the pace changes as we explore the sights of Phnom Penh, Cambodia's capital. The royal palace is beautiful and the Killing Fields disturbing, but I hanker to be back to the personal encounters of rural life. It isn't far upstream to a silk-weaving village, from which we can still see the golden spires and skyscrapers of Phnom Penh across the river. The government is trying to promote traditional handicrafts and foster tourism here, but it has herded the silk weavers into a dispiriting, weed-encrusted theme park, where they sit on concrete platforms in front of their looms, cut adrift from village life.

It is a disappointment, but the visit to the local primary school revives my spirits. There are 295 students in classes of mixed ages. They sit in rows at Dickensian desks, neat in uniforms and gleaming black hair. They sing Twinkle Twinkle Little Star and ask us basic questions in English. I ask some questions, too. Leabphy has two sisters and wants to be a teacher. Tany has five sisters and two brothers, and wants to be a doctor. The children are full of enthusiasm, but what does the future hold? You have to pay for education in Cambodia, and the chances of these village kids ever becoming professionals is remote. Many passengers donate stationary or contribute to Travelmarvel's fund, which recently paid to have ceiling fans installed in the sweltering classrooms.

The final village on our itinerary is Angkor Ban, one of the few not destroyed under the Khmer Rouge regime, and still retaining many of its venerable wooden houses. We are taken for a blessing by Buddhist monks at the riverside temple, jammed with colourful stupas and statues and a giant yellow plaster Buddha. The village is shaded with banana trees. White bullocks and chickens wander. A grandmother with cropped grey hair and silver-knobbed walking stick seems as taken with us as we are of her. As she grins, gaps and gold teeth are revealed. She shows us her grandchildren and chuckles and waves.

It isn't much, just a chance meeting, but aren't human encounters what travel is really all about? Long after I have forgotten what the murals in Phnom Penh's royal palace look like, I am sure I'll think of this old lady from Cambodia, and smile at the memory.

The writer travelled as a guest of Travelmarvel.

CITY EXPERIENCES

A Mekong cruise with Travelmarvel is not only about provincial towns and villages: you can enjoy bright lights and city bustle, too.

HO CHI MINH CITY The two hotel nights before embarkation (or at trip's end) make good sense. Vietnam's largest city has an attractive French-colonial heart, Vietnam War sights, boom-town energy and great eateries.

MY THO You will not see much of this town, 70 kilometres south-west of Ho Chi Minh City, where you board the ship. However, the provincial capital makes a good base for exploring the Mekong Delta, if you prefer independent travel.

PHNOM PENH Cambodia's capital blends an elegant, sometimes sophisticated downtown core with surrounding shanty towns. Highlights include the royal palace, shopping at the Central and Russian markets and a stroll along Sisowath Quay.

KAMPONG CHAM This rather dishevelled Cambodian riverside town has a laidback atmosphere, riverside bars and interesting colonial architecture. Excursions take you to the 13th-century temple of Wat Nokor.

SIEM REAP Your journey finishes (or starts) here, and most passengers opt for an extension to further explore the Angkor temples. The bustling Cambodian town is packed with shops, markets and spas, and has an increasingly raucous nightlife.

FAST FACTS

Getting there

Singapore Airlines flies to Singapore from Sydney or Melbourne (eight hours) and onwards to Ho Chi Minh City (two hours). Return from Siem Reap (two hours) to Singapore with partner Silk Air. Fares from $1350, including taxes, but check the website for deals. Phone 13 10 11, see singaporeair.com.

Cruising there

Travelmarvel's 12-day "Essential Vietnam and Cambodia" cruise is priced from $3695 a person, twin share. Book any Vietnam and Cambodia cruise holiday of 12 days or longer from Travelmarvel's 2015 brochure before February 28, 2015 and receive free return international flights, including taxes. Phone 1300 196 420, see travelmarvel.com.au.

More information 

vietnamtourism.com and tourismcambodia.com.