That is actually amazing you say that Graeme, I am going to Rotto.
It's the most beautiful tourist destination in all of the SW in my opinion.
The major worry is that the native marsupial of Rottnest, the Quokka, is often preyed uopn by idiot leavers, last year several were jammed into a mailbox and needless for me to elaborate on what happened.
It's one of two major leavers destination and helps if you own a boat
I suggest you look it up, next time you're in WA it's worth a visit, only a short ferry ride from Perth!