Final answer:
Boating in an unfamiliar channel requires obtaining local knowledge for safe navigation. When canoeing upstream, staying near the shore minimizes resistance, while downstream, it's best to be in the middle of the stream to utilize the faster-moving water.
Step-by-step explanation:
When boating in an unfamiliar channel, it is advised to obtain local knowledge about the area. This local knowledge can provide guidance on the safest navigation routes, current conditions, and any potential obstacles or hazards that may not be apparent to someone unfamiliar with the area.
When paddling a canoe upstream, it is best to stay near the shore to minimize resistance from the water's current, which tends to be slower along the edges due to friction with the shore. Conversely, when going downstream, the water in the middle of the stream moves faster due to less friction, so staying near the middle can help maximize the canoe's velocity.
Knowledge of these water dynamics is an example of local knowledge that can assist in safer and more effective navigation.