A Sydney Aquarium diver uses a vacuum to clean the gravel in the Great Barrier Reef tank as a Ray Shark swims by September 26, 2006 in Sydney, Australia. The Aquarium is undergoing its annual spring clean to prepare for the school holidays using vacuums, along with sea creatures like Sea Cucumbers, Sea Urchins, Cleaner Wrasse Fish and Sea Stars to help complete the job. (Photo by Ian Waldie/Getty Images)

A man takes pictures at the finish line during the Colour Run at Centennial Park in Sydney August 25, 2013. According to organizers, 15,000 runners registered to complete the 5km (3 miles) course in Centennial Park on Sunday, being covered in blue, pink, orange and yellow powder on their way to the finish line. (Photo by Daniel Munoz/Reuters)

A humpback whale is seen at the beginning of whale watching season during a Manly Whale Watching tour on June 8, 2011 in Sydney, Australia. The first day of winter in New South Wales, June 1st, marks the start of the Humback and southern right whales migration from southern regions to the north to warmer waters. Whale watchers should expect tohave plenty to see with the whale population increasing each year. The migration north continues through July and with the whales returning between September and November. (Photo by Cameron Spencer/Getty Images)

“The Darwin Beer Can Regatta is an event which has been held annually since 1974 in Darwin, Northern Territory, Australia at Mindil Beach. Participants create boats using empty beer cans, soft drink (soda) cans, soft drink bottle and milk cartons. The vessels are not tested for seaworthiness, prior to water events, and those that fall apart are part of the day's entertainment. A great many sundry events go along with the regatta, including concerts, a thong-throwing contest and the "Henley-on-Mindil" competition (named after the Henley-on-Todd Regatta), where participants run their "boats" around like Flintstones cars”. – Wikipedia

Photo: A Darwin Beer Can Boat sails in Darling Harbour on October 31, in Sydney, Australia. Darwin has been named as one of Lonely Planet's top ten cities in the world to visit in it's Best in Travel publication. (Photo by Mark Kolbe/Getty Images for Tourism NT)

A 13-month-old chimp named Fumo carries a “Christmas present” of food treats in wrapping paper under his arm during a Christmas-themed feeding time at Sydney's Taronga Park Zoo, December 9, 2014. Fumo, meaning “chief” or “spear” in Swahili, is one of the latest additions to the zoo's successful primate breeding program. (Photo by Jason Reed/Reuters)

Australian jouster Kimberly Belcher poses for a portrait in her armour on the sidelines of the jousting tournament at the St Ives Medieval Fair in Sydney, one of the largest of its kind in Australia, September 22, 2016. (Photo by Jason Reed/Reuters)

A bodyboarder rides a wave at Mackenzies Bay on May 1, 2011 in Sydney, Australia. A strong east-south-east swell has developed along the NSW coastline with waves between 6ft and 8ft expected to hit the coast for much of the weekend and into next week. (Photo by Cameron Spencer/Getty Images)

Fireworks light up the skyline over Sydney Harbour during the midnight fireworks session as Sydney Celebrates New Year's Eve with the theme of “Time To Dream” on on January 1, 2012 in Sydney, Australia. (Photo by Ryan Pierse/Getty Images)