Catch the whale and “harpoon” it with skewers.

A motorboat pulls a polystyrene foam raft, the “whale”, behind it from one side of a canal or lake to the other among the canoes.
Each crew has skewers in different colours.
When the motorboat passes, they try to harpoon the whale with skewers.
The crew with the most skewers in the whale wins.

Each canoe has a whale attached to it and tries to prevent it being harpooned by the others.