A multi-pronged effort involving police divers, SES officials and rescue specialists searched for the pair on Tuesday after they did not return to their home in southwest Sydney.
The father, aged 47, and his son, 17, from Liverpool, set off on Monday to fish at Storm Bay near the popular Kiama Blowhole, about 115km south of Sydney.
Police were called over concerns for the pair's welfare at 3am on Tuesday and Marine Rescue said it deployed a search boat from nearby Port Kembla at 7.30am.
Given the pair's fishing gear had been found and there had been no communication from them, NSW Police Superintendent Craig Ireland said the working assumption was they had gone into the water.
"There's a lot of people actively trying to find these two fellas … (there's) still hope, (we) never give up, but as time ticks on that hope diminishes," he said.
The wife and mother of the missing fishermen was distraught, Supt Ireland said.
— Westpac Life Saver Rescue Helicopters (@Lifesaverhelo) #SEARCH Lifesaver 21 assisting in search for overdue persons on fishing trip near #Kiama blowhole. Working with @nswpolice, @MarineCommand, @MarineRescueNSW, @NSWSES & @slsnsw. pic.twitter.com/WKWmUqI7B0August 20, 2024
"The best-case scenario is they've found something, a flotation-type material they can hang onto," he said.
"They are capable swimmers, we know that, but there's been no sightings of them, so we're just hoping for the best."
Marine Rescue NSW was also part of the search along with police helicopters and Surf Life Saving NSW officials on Tuesday.
Additional Marine Rescue units plan to join the search when it resumes about 7am on Wednesday, conducting patterns determined by police.
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