[Seabear]

My wife and I took a one week trip from Manaus up the Rio Negro a couple of years ago. Same size river boat, 14 passengers on board, 3 crew and 2 guides. Up the river 300 miles and back to Manaus, canoe trips morning and late afternoon (and sometimes after dark), jungle walks, a visit to a small village and a small town. We didn't see another tourist on the trip, lots of birds, critters, and the magnificent jungle where you learn that if you aren't a predator you are prey. The most fascinating part was meeting people that live on the river, their entire lives revolve around the river, food/transportation/climate.
The trip was one of our most favorite, and, in fact, I am heading back to Manaus in Oct with a buddy for some peacock bass fishing. I really enjoyed reading the journal in the link you provided and forwarded it to my wife. Thanks.