From the Super Mario Wiki
Waterfall Plunge is one of the second routes players can travel in the River Survival mode of Super Mario Party.
The route starts with a slight left before a fast-moving waterfall, which eventually leads to a large drop. A Dash Panel then appears to the right just before a slight right and the first Minigame Balloon behind a rock on the left. Another Dash Panel follows on the left, along with a slight left leading to another waterfall. The second Minigame Balloon follows behind a large rock in the center, just before another slight left indicating the 1,500-meter mark. Another Dash Panel on the left follows, along with a very steep slight right waterfall soon after. A longer drop follows, then a smoother slight right waterfall where the third Minigame Balloon is in front of a rock on the right. The players will then approach the fork leading to either Rugged Ramps or High-Flying Balloons.