Halong Bay is a UNESCO World Heritage site nestled in the gulf of Tonkin. [Photo by Bidisha Bagchi/For China Daily]

A Halong Bay cruise offers an exciting excursion from Vietnam's capital. Bidisha Bagchi hops aboard.

We woke up to a cloudy day in Hanoi.

It wasn't raining. But the sky was in a really bad mood.

We were all set for our Halong Bay cruise, and a cloudy day might cast a shadow over the highlights.

The cruise company bus arrived at its scheduled time and picked us up to take us to the Halong Bay pier from where hundreds of cruise ships leave.

We boarded a small motorboat equipped with life jackets and reached ours. It was a three-story vessel with a deck that offered sweeping views of the lush surroundings and the jade waters.

From the deck, we enjoyed the views of the bay, a UNESCO World Heritage site nestled in the gulf of Tonkin.

The cool breeze was perfect with the sun partially shining on hundreds of islands and islets that create a spectacular vista of limestone rocks of various shapes and sizes.