Hi Mich, i am doing aqua zumba at kurri wed nights at 6.15pm it is really good, pretty gentle, even given the zumba moves lol it's $6.10 per session for 45mins. the instructor is pregnant too.
They also do plain aqua aerobics tues and thurs, same time, i think the same cost. as well as a couple of daytime sessions.
HTH