HAVANA (AFP) - A 56-year-old blind American set off in a kayak on Friday in an attempt to cross the treacherous Florida Straits that separate Cuba and the United States.

Peter Crowley left Havana at 12:35 pm (1635 GMT) in his red boat, accompanied by his son who is guiding him from a separate blue kayak.

As he forges the 150km stretch of shark-infested waters in a push to reach Key West, Florida within 24 hours, a catamaran sailboat will also be following along.

"It means so much to me," said the athlete, a married father of three, who since birth has suffered from optic atrophy - a malformation that prevents the optic nerve from functioning properly.

Crowley, who has only 7 per cent of his vision, is also hard of hearing in both ears. He was forced to remove his hearing aids, which are adversely affected by salty air, for the crossing attempt.

An accomplished athlete, Crowley has already completed several major kayaking feats, paddling more than 125 miles on the Hudson River in 1999 and becoming the first blind man to cross the English Channel in 2003.

Told as a child there were many things he should not try, Crowley said he decided to focus on what he could do, rather than his limitations.

Miguel Angel Diaz Escrich, commodore of the Hemingway International Yacht Club from which Crowley set off, said it was the first attempt to cross the strait by kayak.

Before embarking on the journey, which Crowley said was meant to demonstrate overcoming obstacles and to bring together the estranged United States and Cuba, he donated several devices for the visually impaired to Cuban students.

Completing the cross-ocean journey from Cuba to Florida, whether by swimming or other means, has become increasingly popular with athletes, mainly Americans, in recent years.

In September Diana Nyad swam into the history books, completing a marathon three-day crossing from Cuba to Florida to become the first person to do so without a protective shark cage.