Missing yachtsman Mal Lennon believed to be dead

Yachtsman Mal Lennon, who fell from a yacht in the sea off the Port Stephens coast, is believed to be dead.

Marine Area Command Superintendent Mark Hutchings said the search for the 62-year-old until the early hours of Thursday turned out to be unsuccessful. Two helicopters and marine rescue personnel searched the area but did not find Lennon whose yacht, the Amante, had been swept off Broughton Island at around 11:30 am on Wednesday.

"Due to the conditions and medical advice, we believe that he hasn't survived unfortunately,” Hutchings told reporters. "What we understand and talking to the crew at this point, is that he was at the helm when a large green wave came over the boat and he was swept into the sea."

The Sydney sailor went missing as strong winds and record-breaking rains struck the Hunter region on Wednesday. According to The ABC, he was returning on the 36 cruise racer from Pittwater to Coffs Harbour after a race.

"We believe that during the course of the day and the preceding hours that we did do 100 per cent coverage of the area we believed he was in,” Hutchings added. “(Rescue crews) approached the yacht in the early hours of this morning and attempted to get a tow line to that vessel but were hit by a large wave.”

Marine Rescue helped the Amante and another yacht named Gem to port. However, hostile weather conditions hampered the search for Lennon. According to AAP, the missing sailor was not wearing a life jacket.

According to Hutchings, authorities received mayday call from a yacht with five people on board. They were rescued while one of them suffered a dislocated shoulder.