The journey is expected to take the pair two weeks
Two men are planning to embark on a 212-mile charity venture - in a pedalo.
Andy Miller and Darren Jones said the journey, from Stratford-upon-Avon to Stratford, east London, would take two weeks.
The journey, to raise cash for athletes in Coventry and Warwickshire, will take them along the Stratford, Grand Union and Oxford canals and the River Thames.
The pair will set off in early September and said they hoped to raise tens of thousands of pounds.
Mr Jones, the president of Coventry and Warwickshire's chamber of commerce, said they would be enlisting help from well-known sports people along the way.
He added that they hoped to finish at London's 2012 Olympic Village.
Mr Jones said the pair's pedalo was a "sea-faring" vessel and could face 6ft-high swells in parts of the Thames.
He said they had been training hard but on quieter stretches of water in Coventry and Warwickshire.
He added: "You do get a very sore backside because it's not the most comfortable thing you've sat on in your life.
"And when you're doing eight to 10 hours a day for two weeks it's going to hurt."