Australia - 3 weeks trip - where to dive and how to do..

[sunflower]

Hi all,

we are planning a 3 weeks trip from the great barrier reef to kangaroo island.
We planned to do some guided trips at the great barrier reef and from kangaroo island, but on the trip between - we might mostly use the great ocean road - we read that diving is very nice, too.

Is there anybody with some good ideas where to go diving and how to rent a tank and weights? (as we cannot return it to where we took it)

I would be very happy about some tips :thankyou