Using natural materials and string, build a "boat" that can support the weight of a small stone in a river longer than the other team's
String, scissors or knife, river bank
Tell the scouts that each Patrol has a fixed period of time to gather materials that they can find in the area, construct a shape with the materials and string that they think will float and then tie on the stone. Once the "boats" are ready, launch them one at a time into the stream from the bank and time how long they stay up off the bottom of the stream - don't use distance as that depends on catching a current not floating.
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