Surfers surf at Surf Snowdonia in Conwy, North Wales, September 3, 2015. The surf park, which cost $22.8 million, opened on August 1 and is the world's first commercial artificial surfing lake, according to the company.The pool is 300 metres (980 ft) long and 110 metres (360 ft) wide, containing a total of six million gallons of water. A bi-directional snowplough-shaped wave-generation mechanism, towed on a cable between the two central towers, moves up and down the pool on a three-rail track, generating the waves. (Photo by Andrew Yates/Reuters)

Sand from Montrose Beach whips past Vincent Lagrone as he walks along the lakefront October 19, 2011 in Chicago, Illinois. A high wind warning was issued for the city as winds between 40 and 45 mph are expected to cause 20- to 25-foot waves along sections of the lakefront. (Photo by Scott Olson/Getty Images)

Event curators Harry Parr (L) and Sam Bompas (R) sit in paddle boats in the Truvia Voyage of Discovery installation on the roof of Selfridges department shop on July 21, 2011 in London, England. Selfridges is opening its roof to the public for only the second time since WW2 to host the installation, which includes a boating lake with dyed water and bar. (Photo by Matthew Lloyd/Getty Images)