Marine Rescue NSW volunteers have just completed their busiest year ever, with 481 search and rescue missions across the Illawarra during 2023.

This was a 12 per cent spike on the previous record of 428 set in 2022; and a 51 per cent increase on the pre-COVID number of 316 in 2019.

Of last year's missions, 245 were emergencies and 1091 people were safely returned to shore.

An international UOW student who went missing while swimming off Fairy Meadow Beach in October and a rock fisherman who was swept into the ocean at Kiama Blowhole in May were among the search and rescues.

The student's body was found five days after he went missing, while a Coroner found fisherman Dinh Khang Bui (who went by Michael) died by misadventure.

Not all missions ended in tragedy, with two children and two adults rescued after their fishing boat took on water off Scarborough on August 5. Other fisherman were rescued off Port Kembla on July 4 during a lengthy late-night rescue after the steering broke on their boat.

Of the seven Marine Rescue NSW units in the Illawarra, the Port Kembla unit had the most missions at 169, with 112 of those classed as emergencies. In all, 339 people safely returned to shore.

Jervis Bay conducted 111 missions (251 people saved), followed by Shoalhaven (80 missions), Sussex Inlet (60), Ulladulla (41), Shellharbour (16) and Kiola (4).

The spike in search and rescues was also seen across NSW, with 4786 missions conducted which surpasses the 2022 record of 4055.

Statewide, more than 80,000 trips were logged with Marine Rescue NSW in 2023, almost 16,500 more than the previous year.

Inexperience and complacency are behind many of the calls for help, Marine Rescue NSW Illawarra zone duty operations manager Inspector Stuart Massey said.

"More than half of the jobs that we do out there are 100 per cent preventable with some maintenance or putting enough fuel in your boat," he said.

"Running out of fuel and flat batteries and mechanical breakdowns, while they can happen, we understand that, a lot of them are purely preventative or preventable through maintenance."

Insp Massey said COVID lockdowns and travel bans resulted in a spike in boat sales and now there are more inexperienced boaters on waterways.

"It was one of the activities that you could do. More people bought boats and more people are hitting the water, more people on the water means more rescues," he said.

Marine Rescue NSW are always looking for more volunteers, visit marinerescuensw.com.au to find out more.