A Southsea man completed the first solo swim around Portsea Island, despite being stopped by a police launch because someone reported that a swimmer was drowning in Portsmouth Harbour.
Brian Rann took less than six hours to complete his record attempt on the 14-mile course.
His 14-year-old son, James, accompanied him in the water for more than an hour but dropped out at Portsbridge because he could not cope with swimming at his father’s slower pace.
Mr Rann arrived back at Eastney after five hours and 50 minutes.
The swim around Portsea had only been done once before – 12 years earlier, by a lifeguard team who took six-and-a-half hours.
Mr Rann and his son were experienced distance swimmers.