The marathon, road cycling, triathlon, open water swimming and race walking are the events most at risk.

BBC: Rogge admits Beijing air concern

The first relay runner to take the flame was Greece's Liverpool-born open water swimming champion Spyros Gianniotis.

CNN: 2012 Olympic flame lit in ancient stadium

The club spokesman said the new facilities could also be used by other water sports clubs, including Marlow Canoe Club, Henley Open Water Swimming Club, High Wycombe Triathlon Club and Longridge Canoe Club.

BBC: Sir Steve Redgrave's rowing club receives ?1m grant

She is a fixture of the open-water swimming scene of New York City and currently holds the title of fastest woman to swim around Manhattan at 5 hours, 44 minutes.

WSJ: N.Y.'s Tour de Hudson

Gold in the men's open water 10-kilometer swimming marathon in the Serpentine, the lake in London's Hyde Park, went to Tunisian Oussama Mellouli.

CNN: August 10, 2012 -- Updated 2336 GMT (0736 HKT)

Patten, 21, is no stranger to long distance swimming, having come third in the 10km open water swim and making the final of the 800m freestyle in Beijing.

BBC: Patten aiming to swim the Channel

She began swimming in the lake three or four years ago and said competing in open water is "way quieter" than in a pool.

CNN: 14-year-old swims solo across Lake Ontario

She talks to Olympians and to open-water champions like Lynne Cox to find out why they live to swim, why swimming is man's most sensuous sport (because skin is his largest sensory organ) and why it keeps your arteries elastic, your joints supple, is good for your heart as well as your brain, and offers more than a cursory help in the fight against ageing.

ECONOMIST: Lynn Sherr��s new book offers all the skinny on dipping