Authorities in Beijing fired over 1,000 rain dispersal rockets on Friday evening to ensure a dry opening ceremony of the Olympics at the ‘Bird’s Nest’ stadium.

It was the largest rain dispersal operation in China, and the first time that such technology has been used to guarantee good weather for Olympic opening, said Chinese meteorologists. However, neighbouring areas such as Baoding City of Hebei Province, to the southwest of Beijing received a huge rainfall of 100 millimetres Friday night, and Beijing’s Fangshan District recorded a rainfall of 25 millimetres.

Meanwhile, in Qingdao dawn boat patrols have been searching for the bright green algae that has plagued the venue. In June and July a vast algae bloom clogged about 30 percent of the sailing area. Chinese Olympic organizers mobilised thousands of troops and volunteers to pick it up from as many as 1,500 boats and along the shore.

They are still determined to win the battle, with an armada of 300 fishing trawlers and 1,500 fishermen working off the coast to remove as much as possible before it reaches the racing area, organizers said. Qingdao organizers said that twice a day, at 5 a.m. and at 10 a.m., they send four boats out to check for algae and keep it at bay.