The Duathlon is a run/swim event held over various distances for the various age brackets (as at 1 Feb) and once again is an example of the variety that the AASC provides its members.
| Division | Ages | Run leg | Swim leg |
| Nippers | 9yrs and under | 110m | 25m |
| Cadets | 10 to 12yrs | 330m | 100m |
| Juniors | 13 to 15yrs | 660m | 200m |
| Seniors | 16yrs and over | 1000m | 300m |