I remember reading an article in New Zealand Wilderness Magazine several years ago about a tramp that follows a river path downstream through a canyon with lots of small gentle waterfalls.
At parts of the walk you need to float with your back down the river, and along the way there are lots of opportunities to slide down natural rock waterslides.
I know that's not a lot of information to go off - I can't even remember if it was a day trip or overnighter, but I'm almost 100% certain that this was an article about a trip to Tasmania - does this sound familiar to anyone? Or does it sound like it might be somewhere else in Australia?