The 31-year-old man went for a swim at South Curl Curl beach around 7pm on Saturday after fishing nearby with his friends, who raised the alarm when he didn't return.
Boats and jetskis were launched on Sunday morning as foot patrols continued and helicopters will possibly join the search later, a police spokeswoman said.
The Police Dive Unit has now been called in to assist.
Police said the missing man is described as being of Caucasian appearance with a slim build, about 175cm tall, and with short red hair and beard. He was last seen wearing board shorts.
Local Sue McDonald the beach is hazardous, especially for those who don't know it well.
"A lot of rocks are exposed at the moment, but sometimes they're totally covered in sand so obviously a lot of sand movement and current movement around South Curl Curl," she told the ABC. "So it is a great beach, but just not for swimming off the rocks."
