The rusty boat farts, coughs and chugs slowly along the narrow river channel, a skinny boy perched on its prow shouting directions back to the captain (who does almost as much farting and coughing as his geriatric craft). There's the slop and slosh of oily water round my boots. Three rice rats are busy in the bilges.

On each side of the smooth, coffee-brown water, exuberant subequatorial vegetation leans out, at times forming a tunnel that smothers the sunlight.

This is what I wanted. The Mekong Delta. Romance. Adventure. But as we progress, I note dismally that my guide is diligently confirming all the Mekong Delta boat trip tips that I gleaned during research in Saigon; the man, like many a Mekong guide, is a thoroughly seasoned pain in the rear end.