The man was on board with his dog when he became unwell and disoriented. He called Marine Rescue Bermagui just after 4.20pm on Sunday, July 25.

Radio operators Volker Aebischer and Dennis Walker gave him instructions to activate his EPIRB beacon and maintained radio communication with him until he was located by water police.

Marine Rescue Monaro regional operations manager Glenn Sullivan said water police located the 54-foot yacht just after 9pm.

"Once the water police reached the yacht they were able to transfer him and his dog to the rescue vessel and returned to Eden around 3am on Monday morning," he said.

"A freighter whose crew heard the call over the radio was able to shadow the distressed vessel and shield it from the wind until police arrived."

The yacht was left at sea with the EPIRB beacon activated to allow police and the Australian Maritime Safety Authority to track the vessel until it can be recovered.

"Marine Rescue Sydney is sending out Securite messages to other vessels to let them know about the unmanned yacht, currently located approximately 58 nautical miles south east of Bermagui harbour," he said.

The man was transferred to an ambulance at Eden and was taken to hospital.