Final answer:
The peak aquatic agencies in Australia/New Zealand alongside AUSTSWIM are the ASCTA and SNZ, which oversee coach/instructor training, technique development, and promotion of swimming.
Step-by-step explanation:
Among the peak aquatic agencies in Australia and New Zealand, including AUSTSWIM, are the Australian Swimming Coaches and Teachers Association (ASCTA) and Swimming New Zealand (SNZ). These agencies are responsible for overseeing the training and accreditation of swimming coaches and instructors, the development of swimming techniques, and the promotion of swimming as a competitive and recreational activity.