We were due to take a boat across the river to a deep, narrow bay on the Argentine side of the river near Paraguay, which is a quiet backwater about 25 metres wide, and whose banks are lined with trees full of assorted birds and monkeys. The wind had really picked up overnight and was blowing with enough force to turn the river into a welter of large breaking waves; it was not practical to take the boat across 10 or 15k of open water in the teeth of the wind and with large breaking waves so our trip was postponed until the afternoon, weather permitting....