A man attempting to reach Bermuda from Florida in an inflatable floating bubble has been rescued for the second time in 18 months.

Endurance athlete Ray “Reza” Baluchi set off from Pompano Beach on Friday, despite being warned by authorities that the 3,500-mile ocean journey — also taking in Haiti, Cuba and Puerto Rico — was dangerous.

The 44-year-old, an American resident originally from Iran, voluntarily ended his attempt at 2am on Sunday.

His self-designed “hydropod” was rescued seven miles from the Florida coast by the US Coast Guard, which had been following his progress amid concerns about his and other seafarers’ safety.

On Sunday afternoon, US Coast Guard captain AJ Gould posted on Twitter the letter that had been sent to Mr Baluchi on April 15 instructing him not to undertake the five-month journey.

The letter stated: “I hereby order you not to depart because your vessel and the conditions under which you are attempting to complete your voyage to Bermuda is unsafe. Violation of this order may result in criminal penalties of up to seven years confinement and a $40,000 fine.”

Another US Coast Guard tweet on Sunday criticised Mr Baluchi’s 2014 effort to reach Bermuda via the same means, saying that his subsequent rescue “placed enormous financial burden on taxpayers”, estimated at $140,000.

After his second failed crossing, Mr Baluchi’s spokeswoman, Candace Rojas, told South Floridian newspaper The Sun-Sentinel that he would “definitely” try again.

“Right now, he is just disappointed about having to end this one,” she added.

On Mr Baluchi’s personal website, Runwithreza.com, it states: “Everyone wants to know how Reza Baluchi will be successful in his travel through the Bermuda Triangle.

“Reza is so confident that he will succeed in this trip because he has carefully articulated every detail it takes to survive.

“Reza will use technology including a GPS, satellite phone and video camera to record his journey.

“He will bring a White House flag to display in every destination.

“He will survive on protein bars, tuna, seawater purified through a filter, Gatorade and chewing gum for sea sickness.”

Mr Baluchi claims he was inspired to undertake his various endurance feats by the events of September 11, to show Americans that Iranians were a peaceful people.

His achievements include a 11,720-mile run around the perimeter of the United States over 202 consecutive days in 2007, raising money for the Children’s Hospital of Denver.