My wonder was, why didn't he just get a motorbike/car? Much easier. Or move closer...
It's in the south american jugle, he can't have a car or a bike, and if he could he wouldn't so that he doesn't destroy the jungle. He doesn't stay at the camp in case they turn on he, he's far enough away to be safe, but close enough to save them if something goes wrong.
EDIT: Another point, why is there a desalination plant in the middle of the jungle? The water should be pure enough.
Didn't you read? The water in the Parabolic River was very salty water. 
if its THAT salty.. why would he be swimming in it..
and GG for that desalination plant if its in Aus..
gonna get carbon taxed to the max