A surfer is silouetted by the sunset on the banks of the Mearim River in Brazil's amazonian state of Maranhao. The Mearim pororoca is one of many Amazonian tidal bores which surfers have begun to take on in a quest for adventure and to help local economies in one of the poorest regions of Brazil.
(AustralFoto/Douglas Engle)

A surfer is silouetted by the sunset on the banks of the Mearim River in Brazil's amazonian state of Maranhao. The Mearim pororoca is one of many Amazonian tidal bores which surfers have begun to take on in a quest for adventure and to help local economies in one of the poorest regions of Brazil.
(AustralFoto/Douglas Engle)