Visitors run away as waves from a tidal bore surge past a barrier on the banks of Qiantang River, in Hangzhou Zhejiang province, on August 24, 2013. (Photo by Reuters/Stringer via The Atlantic)

People struggle as waves from a tidal bore surge past a barrier on the banks of Qiantang River in Haining, Zhejiang province, August 22, 2013. As Typhoon Trami landed in eastern China, tidal level in Qiantang River was recorded at 6.6 metre high with surge reaching 1.3 metre high, local media reported. (Photo by Reuters/China Daily)

The incoming spring tide on the River Severn in Gloucestershire, on March 2, 2010. (Photo by Flickr user PapaPiper)

A remote controlled helicopter hovers over the Qiantang River as tourists gather on the river bank to see the soaring tide in Haining, Zhejiang province, on September 13, 2011. (Photo by Reuters/Stringer via The Atlantic)

Spectators flee as waves created by a tidal bore crash over a barrier on the Qiantang river at Hangzhou, in east China's Zhejiang province, on August 31, 2011. (Photo by AP Photo via The Atlantic)

A crowd of Chinese tourists run away as a tidal bore breaks through the dam by the Qiangtang River in Haining, east China's Zhejiang province on August 31, 2011. Visitors gather to experience the Qianjiang Tidal Bore from early morning, an annual tradition for the residents living nearby. (Photo credit should read STR/AFP Photo)

Brazilian surfer Savio Carneiro celebrates as catches the thunderous “Pororoca” tidal bore wave during the national pororoca circuit final on the Mearim River, some 30 km inland, in the Amazon jungle near the northern Brazilian city of Arari, on April 19, 2003. The term “Pororoca” comes from the Amazonian indigenous term meaning “destroyer, great blast”. The feared and thunderous waves have capsized boats and washed away most anything in its path. (Photo by Sergio Moraes/Reuters via The Atlantic)

A kayaker rides the biggest bore tide of the summer as it roared into Turnagain Arm south of Anchorage, Alaska, on June 5, 2012. (Photo by Ron Barta/AP Photo via The Atlantic)

Surfers Adilton Mariano and Rodrigo Resende ride the Pororoca wave in the Araguari river in northern Brazil, on May 18, 2003. (Photo by Enrico Marone/AP Photo via The Atlantic)

Villagers ride the Pororoca wave in a canoe as it passes near their town of Sao Domingos do Capim, northern Brazil, on March 12, 2001. (Photo by Paulo Santos/AP Photo via The Atlantic)

Surfers enjoy the Severn Bore near Newnham along the River Severn on March 2, 2010 in Gloucestershire, England. (Photo by Matt Cardy/Getty Images via The Atlantic)

Visitors run away from a tidal bore wave as it surges over a barrier on the banks of Qiantang River, in Hangzhou Zhejiang province, on August 25, 2013. (Photo by Reuters/Stringer via The Atlantic)

Spectators get to their feet, after being swept down a hill by huge waves while watching tides of Qiantang River on August 22, 2013 in Haining, China. (Photo by ChinaFotoPress via The Atlantic)

A tidal wave hits a bank along the Qiantang River on August 22, 2013 in Haining, China. The 12th typhoon Trami landed in Fujian province at 2:40 am and led gales and heavy rainfalls in east China. (Photo by ChinaFotoPress)

People struggle as waves from a tidal bore surge past a barrier on the banks of Qiantang River in Haining, Zhejiang province, August 22, 2013. As Typhoon Trami landed in eastern China, tidal level in Qiantang River was recorded at 6.6 metre high with surge reaching 1.3 metre high, local media reported. (Photo by Reuters/China Daily)

A tidal wave hits a bank along the Qiantang River on August 22, 2013 in Haining, China. The 12th typhoon Trami landed in Fujian province at 2:40 am and led gales and heavy rainfalls in east China. (Photo by ChinaFotoPress)

Policemen and residents run as waves from a tidal bore surge past a barrier on the banks of Qiantang River in Haining, Zhejiang province August 31, 2011. As Typhoon Nanmadol approaches eastern China, the tides and waves in Qiantang River recorded its highest level in 10 years, local media reported. (Photo by Reuters/China Daily)