What is that smell?

Went on an all-day excursion snorkeling around the islands south of Phu Quoc island. After 20 km of dusty road we get to the fishing pier where we catch our boat. Stepping carefully across the rickety planks, praying that we don't fall through to the fetid water below, we are accosted by the foulest stench we have ever experienced. Drying and rotten shrimp roasting in a humid, 30 degree celcius climate. Set a personal best for breath-holding.

Paul