One of the early classics of Western anthropology is Bronislaw Malinowski's Argonants of the Western Pacific which studied the long Trobriand Kula trade voyages in their ocean-going outrigger canoes and the complex circular exchange route of gifts between the trading partners. On the rivers, men from villages far up-stream, cut timber and make a raft of the logs. They put up a small shelter, tie a canoe to the raft , sometimes load the whole family and dogs on, take a few chickens to eat on the way, and drift down to a sawmill, sell their timber, buy supplies at the trade store and then slowly paddle back home. Without an outboard motor, this round trip takes weeks. PNG The addition of outboard motors make travel much faster than with paddles or sails, but fuel is expensive and sometimes difficult to get.
Engines break down in the middle of nowhere.
In the Asmat, only kerosene motors are used and we have to ship our fuel drums around ahead of time by the small coastal freighters, as people usually only have enough for their own use and are reluctant to sell any. Sometimes we double the canoes and put a platform across to make stacking the artifacts easier, then pitch a blue plastic tarp for shade. It's comfortable in a canoe if it's moving. The motor is noisy, but the vibration is soothing, and the speed generates a cooling breeze, but when you stop, the sun beats down. And when it storms, it's amazing how freezing cold you can feel in the tropics in the middle of a big, endlessly winding river in a driving rain.