Busselton is one of the few places in Western Australia where you can watch the sun rise over the ocean, and then watch it set over the ocean too.
Busselton Jetty hosts an amazing underwater observatory at the end. You can catch a train along the 1.8km jetty to reach it.
The observatory is a huge cylindrical building submerged and then bolted to the ocean floor. What you see outside is a world of huge timber pilons and sea life that have made it their home.