The World's largest waterfall is underwater - The Denmark Strait Cataract

• The world’s biggest underwater waterfall is located in the Denmark Strait between Greenland and Iceland. Arctic water from the Greenland Sea drops precipitously into the depths of the (slightly less chilly) Irminger Sea.
• The amazing thing about the Denmark Strait cataract is that it dwarfs anything you’d see above the waves. Its water drops almost 11,500 feet, more than three times the height of Angel Falls in Venezuela, normally considered Earth’s tallest waterfall. And the amount of water it carries is estimated at 175 million cubic feet of water per second. That’s equivalent to almost two thousand Niagaras at their peak flow.