As twilight turns to dusk, it feels as if our ship is being slowly swallowed up by the land and seascapes.
As my eyes soak up the ethereal scene, I'm almost convinced the local stories about dragons could be more than a fairy tale.
Soaring limestone karsts stretch towards a pale lavender sky. The sun polishes the water with a golden glow, as silver clouds fade into the sunset. Water laps against the ship's hull as wine glasses clink and laughter drifts from the ship's Sun Deck above.
Vietnam, according to legend, was once protected by dragons, and Halong (which means descending dragon) Bay was where the dragons came down to earth in a major battle.
The dragon defenders spat out jewels and jade that grew into soaring limestone islands upon which enemy ships were wrecked.
The bay where the mother dragon descended was called Halong, while the bay where her children appeared was named Bai Tu Long.
So captivated have I been by the sunset that I missed the hour-long Vietnamese cooking demonstration aboard our cruise. The Au Co launched under two years ago and is one of the newest luxury ships on the bay.
My two-night cruise is part of an 11-day tour of Vietnam with Wendy Wu Tours. From Hanoi, a minibus whizzes past panoramas of farmland, rice fields and towns in the Red River Delta.
Aside from a bumpy section of road close to Halong Bay, the roads are reasonably smooth. Even so, the journey takes four hours, but it's worth the trip to see this UNESCO World Heritage site.
Halong Bay is in the Quang Ninh Province of Vietnam. It covers about 1553 square kilometres and has 775 islets, mostly limestone, formed over 500 million years.
Waiting to board at the cruise company's outdoor check-in lounge at Tuan Chau dock, we have cool towels, soft drinks and a ringside view of the red carpet down to the water, where boats and motorised tenders ferry groups of passengers between ship and shore.
The Au Co has 32 cabins, including two charming Long Quan suites at the bow, furnished in French provincial style, and two Au Co suites with roomy terraces. Deluxe and executive cabins have polished timber floors, dark timber wall panelling and crisp all-white bedding.
Each cabin has a mini bar, hairdryer, safe and satin bathrobes. Timber-framed french doors with floor-to-ceiling glass panels lead to a small balcony with timber chairs and table.
The ship's restaurant follows the concept of Wu Xing, the five elements of Chinese philosophy: fire, wood, metal, water and earth. The chef has created fusion dinner menus of five courses, each representing an element. Vietnamese and Western dishes such as chicken and pomelo salad, spring rolls, clam chowder, basa fish with mushroom sauce and creme caramel with sweet potatoes feature.
While the food isn't fine dining by Western standards, dishes are full of flavour and well presented. The waiters are attentive and endeavour to please, but not every staff member speaks English so communication can be frustrating.
This ship is marked out by its itinerary and the activities it offers. Hundreds of ships cruise around Halong Bay and most follow similar routes, making the popular spots on the bay quite crowded. So the Au Co's route to Bai Tu Long Bay, Lan Ha Bay and Cat Ba Island is a selling point (although Cat Ba Island is temporarily off the itinerary).
Bai Tu Long National Park is relatively empty but it is just as beautiful as Halong Bay. After lunch at Bai Tu Long Bay, we climb into kayaks and paddle to Vung Ha beach. There's only one other kayaking group there and it feels like we're exploring an undiscovered region. Another time, we strap on headlamps and paddle into a dark cave, with bats hanging from the roof, and paddle around the bay through another cave and into a lagoon surrounded by limestone cliffs.
My favourite excursion is a visit to Vung Vieng fishing village, where we meet children at a local school before climbing into wooden rowing boats for a tour of the village's colourful timber floating houses. The verandahs are a jumble of nets, potted plants, fishing equipment and clothes drying on lines.
On our last day, we anchor near Sung Sot (surprise) cave on Bon Ho Island, which is a busy area of the bay. It's raining lightly so, donning a plastic poncho, I head up the stone steps to the entrance.
It's impossible to avoid the crowds here but the view is worth the effort.
The stalactites and stalagmites in the cave are impressive.
We follow our guide along the path, which twists and turns through three chambers. She points out formations that resemble tigers, penguins and dragons.
We learn that Vietcong hid in these grottos in the Vietnam war. But the dimly lit chambers look so romantic I can hardly picture it. Just another one of captivating Vietnam's surprises.
The writer was a guest of Wendy Wu Tours and Cathay Pacific Airlines.
GETTING THERE Cathay Pacific operates flights to Hong Kong. Dragonair has four connecting flights a week to Da Nang and daily flights to Hanoi. See cathaypacific.com. House of Travel currently has a Cruise Halong Bay deal.
CRUISING THERE Wendy Wu Tours has a range of fully inclusive escorted group tours of Vietnam, deluxe escorted tours, private departures of group tours (land only) and itineraries for independent travellers. A one-night cruise aboard Bhaya Cruises costs from $342 a person twin share and includes transfers from Hanoi, two nights' accommodation and sightseeing.
A three-day package that includes return private car transfers from Hanoi and two nights on board The Au Co with all meals and sightseeing costs from $936 a person twin share.
GOING THERE November to February can be misty and visibility is lower than the rest of the year. The best time to visit Halong Bay is between March and October.
MORE INFORMATION wendywutours.com
- FFX Aus