But when he makes good on his offer - submitting to surgery and a week of painful recovery - it will all be for the good of a stranger.

Mr Wicks, a NSW Ambulance paramedic attached to Kiama station, will undergo surgery at Westmead Hospital today after he was found to be a match for a person with serious health problems.

He was one of about 50 area surf lifesaving volunteers who signed on to the Australian Bone Marrow Donor Registry in 1997, when Gerringong lifesaver Bob Churton was diagnosed with leukaemia and required a transplant.

Mr Churton's cousin was identified as a suitable match, but the father of four ultimately died from complications resulting from his condition.

"Bob was a well-respected family man - and extremely community minded," said Mr Wicks, 38.

"It was quite hard, and you just feel for his family. If you can help somebody - if you can help a family not go through what Bill's family - and a lot of other families - go through, you definitely would."

Mr Wicks will be placed under general anaesthetic for the procedure.

Waiting for him to wake will be his wife of 16 years, Katie Wicks.

The two started dating when he was 15 and she was 13, and went on to have three children together - Kirralee, 10, Harrison, 9, and Darcey, 6.

"Shane is just one of those people who genuinely likes to help," Mrs Wicks said.

Mr Wicks said he hoped his experience would show his children "it doesn't hurt to help somebody", and would encourage others to sign on to the Australian Bone Marrow Donor Registry.

The requirements for a donor match are so specific that only about one in 1000 would-be donors are asked to make good on their offer each year.

Mr Wicks will get progress reports of the person who receives his bone marrow after six months and 12 months, with the details decided by the recipient.

"Hopefully we'll find out how the person is - how they're travelling - that they went on to have a long and fulfilling life and beat whatever disease they were fighting," Mr Wicks said.