Sheffield resident Jonny Sammut spotted the discarded bike floating just below the water in the River Don by North Bank yesterday afternoon.
The incident is just the latest in a long line of reported vandalism of the bikes since the scheme was launched in January this year.
A fleet of 1,000 bikes were deployed in Sheffield with customers able to hire one for 50p for 30 minutes.
Users download a free app to locate and unlock a nearby bike and they can be locked up again anywhere in the city when they are finished with.
A number of the bikes were initially damaged in Sheffield, with incidents reported to South Yorkshire Police in the first few days of the scheme being launched.
Many of the bikes have been vandalised or spotted dumped in trees, ravines or taken miles out of the city centre with the locks broken.
Police have said they will not be responsible for collecting the new bikes and told residents to report any damaged or abandoned bikes to Ofo UK.
Officers criticised a minority of people for 'spoiling' the facility for the majority of people by abusing the new facility.
A team of Ofo marshals operate around the city seven days a week, bringing back bikes that have been left outside the zone.
Ofo have previously said that a 'tiny minority' will not ruin the scheme.
Adam Rose, Operations Manager for ofo in Sheffield, said: "There has inevitably been a small amount of misuse of our bikes, but levels of vandalism are low and the vast majority of our fleet in Sheffield is being used in a responsible and considerate manner.
"When misuse does occur we have a dedicated team of marshals on the ground to respond swiftly.
"Our launch in Sheffield has proved a huge success and we’re encouraged by how popular the bikes have been with locals."