It's the type of scenario big wave surf movies are made of.
However, authorities have advised those in affected areas to monitor conditions, take proper safety precautions and even consider staying out of the water.
Surf and swell conditions are expected to become hazardous for coastal activities such as rock fishing, boating and swimming, with a hazardous surf warning in place for the Sydney coast, Illawarra coast, Batemans coast and Eden coast for Friday and Saturday.
The Bureau Of Meteorology announced that a deep low pressure system crossing the southern Tasman Sea during Thursday and Friday will bring a large swell to the NSW coast over the next few days.
Southern and central parts of the coast can expect a steady increase in swell during Friday afternoon and evening, creating hazardous surf conditions.
BOM meteorologist Helen Kirkup said the southerly wind came through the Illawarra overnight on Friday, and behind that the swells were starting to build.
She said waves could average between two-and-a-half and three metres on the Illawarra coast, although the places more exposed to the southerly and located off-shore could get an average of four metres.
"Those actually reaching the shore, there's a period of time late Saturday that could reach three-and-a-half metres, but it's about which beaches are more exposed to the south," she said.
Ms Kirkup said Saturday would feature more obvious big wind and swell conditions, while Sunday would be less obvious, meaning the public needed to be aware that bigger wave sets could come in.
"This swell is pretty much southerly today (Friday), and it's going to start building this afternoon," she said.
"By Saturday, we're really looking at a combination of strong winds on the waters, as well as some decent-sized swells, so big wave heights getting towards four metres.
"It will build Saturday and it will be quite big swells, but the wind's going to start easing off later on Saturday, so what we're going to have then is calmer conditions.
"Then we're going to get those big sets coming through from the south... So we are looking at wave heights of around three metres through Saturday afternoon and into Sunday.
"On Sunday, it will start easing off by the evening, dropping around to maybe two-and-a-half metres on average, but the time between the bigger waves will increase and there should be reasonably calm conditions in terms of the wind.
"Those conditions can be deceptive, because it makes it nice for those who are good at surfing, and tempting for those who are not so good, because of the wind state having dropped."
Therefore, Ms Kirkup suggested beach-goers watch the water for 20 minutes before deciding to jump in, and swim between the flags.
NSW Police Force, Marine Area Command has advised that people in areas affected by hazardous surf warnings should consider staying out of the water, and avoid walking near surf-exposed areas.
"In the wake of a number of rock fishing fatalities this year, rock fishers should avoid coastal rock platforms exposed to the ocean, and seek a safe location that is sheltered from the surf," they said in a statement.
"Boaters planning to cross shallow water and ocean bars should consider changing or delaying their voyage.
"Those boaters who do choose to go out should carry the appropriate safety equipment and wear a lifejacket."
This story Monster surf conditions expected along Illawarra coast this weekend first appeared on the Illawarra Mercury.