Mr McCartney was getting acquainted with reptiles and discovering and identifying rare marsupials years before the late Steve Irwin happened along.

Earlier this month 72-year-old Mr McCartney, now at a stage in life where he’s concerned about fitness, was back swimming with freshwater and saltwater crocodiles at Lake Argyle in the Kimberley Ranges of Western Australia. It is his third visit to Lake Argyle.

Mr McCartney was a ranger at the Sir Joseph Banks Wildlife Refuge on Mount Panorama and still works as Winburndale Dam ranger.

He became known for his love of and expertise with reptiles.

A self-taught bushie who spent time with indigenous clans, he was the man to turn to when injured wildlife were rescued from roads in the Bathurst district.

Mr McCartney raised orphaned eagles, teaching them to fend for themselves, before releasing them. Goannas and echidnas were among his favourites.

In latter life Mr McCartney has been working to keep his fitness levels up, swimming almost daily.

He was among 50 competitors who contested either a 20 or 10 kilometre swim course on Lake Argyle, an impoundment 18-20 times larger than Sydney Harbour and containing a freshwater and saltwater crocodile population estimated at 22,000.

Was Mr McCartney scared?

“No, it was beautiful and relaxing once you were out on the lake and in the water,” he said. “Water temperature was 30 degrees Celsius. Winburndale, where I usually swim and train, was 13-14 degrees Celsius.

“But I’ve been training for Lake Argyle at the Bathurst Aquatic Leisure Centre, swimming 10-14 kilometres per week most weeks of the year.”

Mr McCartney had been concerned more about his health going into the 10km swim than the crocodiles, because he’d been suffering severe back pain that gravitated to his hip.

“Once I got into the lake everything came good,” Mr McCartney said.

“Competitors who did 20km were dropped in at 6am, they’d done half the distance when we started at 10am.

“I completed the swim in three hours and 27 minutes and didn’t feel a twinge. It was a personal best.

“Even now, a few days after the swim, I still feel really good, I could go and do it all over again.”

The Lake Argyle Challenge requires each swimmer to be accompanied by a kayaker.

Mr McCartney had two companions from Kununurra, the nearest town to Lake Argyle. Ainslie and Sarah were there with him all the way with a power boat just a short distance from where they were swimming – just in case of an emergency of the crocodile kind.

The challenge offered $7500 in prizemoney.

Darwin duo Namiko Kobayashi and Sascha Saharov were first across the line in two hours 26 minutes.

Mandurah’s Barbara Pellick won the solo 10km swim, for the second time, in two hours, 41 minutes. First across the line was Kununurra’s Glenn Taylor in two hours 35 minutes.

Mr McCartney would like to hear from anyone who would like to contest the next Lake Argyle swim.