Charley and Theresa Riley, of Auckland, married for 11 years, renewed their vows at the Trang mass underwater wedding ceremony.

Charley and Theresa Riley, of Auckland, married for 11 years, renewed their vows at the Trang mass underwater wedding ceremony.

A shoal of angel fish has appeared in the Bangkok airport hotel. They trip to and fro, some carrying bits of paper, some participants, and all en route to the big event in Southern Thailand. The girl fish wears a veil and pink lipstick; the boy sports a bow tie. Together they proclaim "the sweetest ceremony", the Trang Underwater Wedding 2005.

We are an army of T-shirt wearers; an international tour group with one aim in mind - to don scuba gear and get hitched in one of the oddest mass mating rituals around, or to cover it for the world's bewildered press.

Trang Province is on the Southern Andaman Coast, tucked away to the southeast of Phuket and Krabi. Its shores largely escaped the horrors of the Boxing Day tsunami, although two people died when 2m waves swamped the beaches and pier.

But the good people of Trang have cleaned up and moved on. The Underwater Wedding is in its tenth year and the Valentine's Day romance fest is a chance for the town and its environs to put on its cultural glad rags and welcome guests from around the world.

The party begins when we touch down at Trang Airport. Our plane is packed with Thais, Spaniards, Germans, Swedes, Taiwanese, Chinese, Italians, Malaysians, Koreans, Americans, Filipinos, Danes, Norwegians, Greeks - 48 couples and New Zealanders Charley and Theresa Riley, who have been married for 11 years but chose to renew their vows wearing rubber.

(Never ones to take the path well trodden, their first ceremony was Auckland's first medieval wedding, which also attracted media coverage.) The licensed PADI divers own Dive HQ in Westhaven and Greenlane and loved the idea of expressing their passion for each other through their passion for being beneath the waves.

They emerge from the plane waving a New Zealand flag and join the others on the runway amid a friendly riot of dancing and drum-beating from Thais wearing costumes that represent their country's provinces and religions. Thai women throw bougainvillea blossoms and bestow garlands. Pink hearts and smooching angel fish are everywhere. The welcoming speeches are the first of many bureaucratic blessings we will hear over the next three days.

We pile on to a fleet of air-conditioned buses and charge into town to the sanctuary of a large hotel.

In the afternoon we travel by bus to City Hall for the proper parade. People wear glorious silks and golden adornments. Girls are lacquered and lippied like baby goddesses, their mums carry colourful woven dowry bags and the traditional klongyao (long drum) bands are a fluoro explosion of red, green, pink and orange.

We sit on the hot tarmac, serenaded by the Wichienmatu Marching Band and the magnified sound of the blood coursing around our overheated brains.