Chis. I have seen your article about rowing in Argentina. This is a gift for you. Our Odyssey to Uruguay (in five days, 160km rowed).That's twenty miles a day - well done, guys! Here is a slideshow of their epic trip:
They started in the Sarmiento River and braved the river buses in the Delta and the monster ships in the Parana and Uruguay rivers to row to Carmelo in Uruguay.
They returned via the River Plate (I had always assumed that we had simply anglicised the Spanish Rio de la Plata, but apparently it means 'River of Silver', and plate was the Tudor word for silver so it is actually a proper translation).
They battled 100 degF (38 degC) temperatures and blazing sun - one of them got a fever and had to cox beneath an improvised tent.