Well you really have no other option, you will ride in one of these. This is the only way to get to the various lodges in the jungle. They go pretty fast and keep your eyes open for wildlife.
Here's a tip: everyone on the same side of the canoe should't get up at once ;)
A few kilometer's hike followed by a 5-10 minutes boat ride in this narrow stream will lead you to spectacular entry into the lake. Our guide said a few weeks ago, a work was attacked by an anaconda in this stream!
Transportation from Puerto Maldonado to the various eco-tourism lodges on the Tambopata River is strictly by motorized canoe. Lifejackets are a requirement, and the motors can be tempermental.
The water levels on the Tambopata River vary over the course of the year. For most of the tourist lodges, this is not a problem, however some lodges further down the river may be 'cut-off' from the river - the canoe may be able to get through, but you might be asked to help pole, or portage the canoe
This converted truck with thatched roof and bucket seats is fun to ride. But watch out for bumps on the way to the boarding place for the boat.