Search continues for missing rock fisherman Michael Bui at Kiama

The Campbelltown man, who is in his 70s, was swept off rocks on Tuesday evening and strong winds have been making visibility difficult since then.

"Conditions are very average - a confused sea it's called," Marine Rescue NSW Inspector Stuart Massey said.

"Swell is about 2-3m and the wind has backed off a bit."

Search crews have been scouring the ocean since Mr Bui was washed off rocks near Kiama Blowhole just after 6.45pm on Tuesday. He was not wearing a lifejacket.

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Despite a strong wind warning for the Illawarra coastline on Thursday, police, Marine Rescue NSW and surf lifesavers entered the water at 8am to continue their search.

The family of the Campbelltown man gathered at Kiama on Wednesday as they desperately hoped he would be found.

Among them was Tan Tran who said Mr Bui was an experienced fisherman.

"He's been fishing for a long time, he's been here for 40 years. I don't know what happened," he said.

Marine Rescue NSW Inspector Stuart Massey said the missing fisherman was seen in the water for a short time after he was swept in on Tuesday.

"He was witnessed going in by his mate and he was calling out for help," he said.

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NSW Police Chief Inspector Darren Brown said conditions were heavy and quite dangerous as searchers looked for the fisherman on Wednesday.

Mr Massey said rescue crews are conducting parallel line searches of the area, from Bombo Headland to Black Rock in the south.

"Once they do a run a they will move half-a-mile east and run the same pattern," he said.

"Our crews will gradually move further east with each leg until they've covered off a 40 square nautical mile area," Mr Massey said.

Chief Insp Brown urged other rock fishers to always wear a lifejacket and to monitor conditions.

"If it's too rough or dangerous, don't go fishing," he said.

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