We seem to get from Da Nang to Can Tho in the blink of an eye, via a domestic flight which leaves on time and arrives early followed by a taxi driver with Formula 1 aspirations. Our base in Can Tho is in the Ninh Kieu district, close to the quay of the same name, and as we take our first stroll and look out across the water, there is a serenity which we think is like a Spanish siesta, but will come to realise later that it is something else entirely. The mighty Mekong River travels some 3,050 miles from its source high on the Tibetan Plateau down to…