How deep is the water at the base of Niagara Falls?

The water at the base of the Horseshoe Falls (the big one) is about 170 feet deep. That's roughly the height of a 17-story building. Don't let the churning white foam fool you—it's a massive plunge pool carved out over thousands of years. The American Falls side is shallower, maybe 20-30 feet at the base, because the rock pile at the bottom breaks up the drop.

If you're asking because you want to swim or boat there, absolutely not. The currents are deadly, and the Maid of the Mist boats stay well clear of the direct base. For a solid view of the depth, take the Journey Behind the Falls experience ($25 CAD/adult, runs year-round) and look out from the observation deck near the water level. You'll get a real sense of how much water is churning down there.