Most calls are admittedly due to lack of boat maintenance - not enough petrol or flat batteries - says Mr Kribb, Marine Rescue NSW's State Operations Director.

But then there's calls that are literally a matter of life or death - and in the past 12 months the dedicated volunteers at the Hill 60 base have conducted over 40 lifesaving missions.

That's thanks to their efforts - and a $75,000 IMB Bank Community Foundation grant last year which enabled the barely-functioning radio operating room base to be transformed into a state-of-the-art facility.

It now has the latest technology, while the grant also funded the installation of more radio towers along the South Coast so Marine Rescue can guarantee 24-hour coverage from the Royal National Park to Sussex Inlet.

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Mr Kribb said not all rescues were a success - including a mission last August to search for a rock fisherman who had been swept off the rocks at Hill 60. Tragically the man had drowned.

"Unfortunately in the area, we have a lot of rock fishers who go missing," he said. "Those rescues often have a negative result."

Mr Kribb recalled another tragedy where a man and woman died after their yacht ran aground off Port Kembla in 2009 during a race from Sydney to Flinders Islet.

"That was one of the most tragic incidents," he said.

"Two sailors lost their lives in the middle of the night.

"The Mayday call was received, boat crews were sent, and NSW Police Marine Area Command sent rescue helicopters. That was one our the biggest rescue operations."

Marine Rescue's regional operations manager Bruce Mitchell recalled a successful rescue of two fisherman who went for an early morning fish off the coast of Kiama but found themselves in trouble.

They were found 27-hours later by a deep-sea fisherman clinging to their overturned boat near Ulladulla in 2008.

"That was a big search too," Mr Mitchell said. "Police and rescue aircraft were looking for them. A man on a trawler thought he had seen them and went and saved them.

"They were lucky it is was a warm day and that they could sheltered between the two hulls of their boat."

IMB Bank executive officer Robert Ryan said the foundation was set up to invest in not-for-profit, volunteer and community assets, such as Marine Rescue.

"Marine Rescue is a community asset that is doing great work for the Illawarra and South Coast," he said.

"The money was used to upgrade the digital technology and connectivity so volunteers could more easily track and communicate with vessels along the coast."

Mr Kribb said the more than 50 volunteers carried out a range of roles at the radio operating room.

"The most important one is monitoring VHF-Channel 16, which is the emergency channel,"he said. "We do that 24-hours a day.

"Once the emergency call comes in, the operator acknowledges the call, then the operator gets key information from the caller.

"They find out what the vessel is, its position, what the problem is, how many people are on board and who needs to be rescued."

Mr Kribb said the operator then dispatched Port Kembla and Shellharbour boat crews.

"We work with NSW Police Marine Area Command, who send police vessels, helicopters and search aircraft to assist," he said. "Our operator maintains contact so we have the best information and we use the technology to track the vessel so we can get to it as soon as possible."

There's a range of calls for help, and the volunteers are prepared for anything.

"Water in the fuel, not enough petrol or flat batteries are our most common types of rescue," Mr Kribb said.

"We also assist when vessels run aground while at sea, people falling overboard and being hit by propellers as well as missing fisherman."

Volunteers also logged when boats left and when they expected to return so a search could start if vessels did not return on time.

Mr Kribb said the role could be stressful when an emergency radio call came through on the internet-based phone system.

"I'd like to think I am a pretty calm person but the heart rate definitely goes up once you hear the word, 'Mayday'," he said. "But then the training kicks in."

Pauline Stang used to work with radio operating systems so volunteering at the Marine Rescue base was a good fit for her after she retired.

"It has been really rewarding," she said. "The system is great and easy to use," she said. "I also get a lovely view over the ocean."