Corporal Jason Nunn, from RAAF Williamtown, was crowned ADF Ironman after crossing the line ahead of his Defence Force rivals at the recent Australian Ironman Triathlon, held at Forster on the NSW mid-north coast.

CPL Nunn completed the 3.8km swim, 180km cycle and 42km run in a time of 10hrs 4mins 36secs to finish in 153rd place overall out of more than 1000 competitors.

Air Force athletes dominated the ADF standings, filling four of the top five places. SGT Allan Lawrence was the second ADF participant across the line, LAC Martin Lewis finished fourth and FLTLT S. Jones crossed in fifth.

AB Louise Ryan, meantime, won the ADF Ironwoman crown.

Although pleased with his performance, CPL Nunn, a veteran of three Forster Ironman races, was a little disappointed at not improving on last year's result, when he finished 25th overall in less than 10 hours.

'I wasn't able to train as much as I would have liked for about two months before the race because of other things,' CPL Nunn conceded.

About 10 kilometres into the run leg, CPL Nunn said his knee began to lock up and he even considered dropping out of the race.

'I had my family up from Melbourne so I didn't want to disappoint them,' he said. 'It was all about gritting my teeth and getting through the next 30km, which I did. It was a big battle all the way, though.'

Thirty-three other ADF Triathletes became Ironmen at Foster.

In the event's history only 252 ADF triathletes have been able to call themselves Ironmen, becoming members of a very special club.

It's a club, however, that CPL Nunn is thinking of leaving. A former cyclist, he is seriously considering tossing his running shoes under the bed and returning to the bike full time.

By Ben Caddaye