Cimmino, 52, lost his right leg below the middle of the femur aged just 15, when medics were forced to amputate the appendage as it was riddled with an aggressive form of bone cancer.
In September, Cimmino, originally from Torre Annunziata, Campania, hopes to swim from Kay West, on the southern tip of Florida, to Havana, Cuba.
If all goes to plan, the swim should take 60 hours, during which time he will brave strong currents, sharks and jellyfish in the Gulf of Mexico.
Cimmino says he is undertaking the swim in order to raise awareness of the difficulty disabled people face in day-to-day life.
“A person cannot be disabled - it's the society around them that is disabled," he told The Local.
"I'm not scared about the swim either," he added. "In fact, the only thing that scares me is humanity's grim ability to sow the seeds of marginalization each day."
But the swim also has a scientific goal.
Throughout his six month training programme in Florida, Cimmino's performance will be closely monitored by a team of scientists from the Campus Bio-Medico University in Rome, who will be measuring his performance to gather data about his body.
“We are hoping the data can shed light on extreme endurance training,” researcher Eugenio Guglielmelli told newsItaliane. “We will also be able to use the data to help him improve his performance and technique.”
Curiously, Cimmino only learned to swim when he was 40, hoping the exercise could help him resolve a number of health problems. Since then, he has hardly been out of the water - and has enjoyed much better health.
In his 12 years as a swimmer, he has already notched up a number of extreme swims, notably the 54km New York Swim, which he completed in June 2014. But his attempt in September will be his longest.