I suppose that South America is the continent I'd most like to visit - while there's still some rainforest left ...
So I sometime toy with the idea of taking a boat but my usual source How to travel by train in Central & South America
isn't very encouraging generally. Then, Brazil is such a huge place, I wouldn't be interested in the cities so up the Amazon to the Andes?
Some of the references here are fascinating: http://www.geocities.com/freighterman.geo/mainmenu.html
al about the most leisurely way to travel (one example was Europe to New Zealand - 34 days - one way ....) sounds great if you want to write a novel ... One good tip is to use a refrigerated ship carrying bananas or whatever as they travel fastest and only go from one port to another, not stopping en route