The water is so pure, that you can brush your teeth with it. Maybe try that next time.
Rottnest Islands:An animal called the Ouokka can only be found in this island. It is also great for biking.
This is the Ouokka
Fitzroy Island:This island has some of the Great Barrier Reef, and also a trampoline in the ocean.
Trampoline(I tried).
Fraser Island:This Island is the largest in the world, but its ocean is not the best for swimming, but there are beutiful swimming lakes that you can swim in.
Rough waters.
Phillip Island:This is home to the famous Penguin Parade, and this is a really popular surf spot.
Surf Bord.
Lord Howe Island:This island has remains of a volcano and a huge variety of wildlife. It also has huge mountain peaks and coral pools.