You can in/out of Apollo Bay from Melbourne with this Vline Bus Service. The timetable is very punctual. It you don't want to miss a bus, please be at the bus stop 10 or 15 minutes earlier.
The bus starts from Geelong bus terminal, and end here at Apollo Bay Visitor Information Center.
It is a comfortable bus ride.
Please check out its website for the timetables or prices.
My wife and I rented a car in Melbourne for our Great Ocean Road Adventure. Driving was easy despite the winding and hilly roads. We arrived in Apollo Bay and made this our first overnight stop on our journey. One in town we parked the car at the motel and walked the town (it's small enough not to need to waste the fuel).
We rented a motor home for our trip along the Great Ocean Road, slow and ponderous it suited our needs perfectly. The road is 270 kilometers long and in peak season is jammed with holiday traffic, we arrived early in the season and were treated to a fantastic drive on open roads with clear views and room to stop and marvel. Its worth making a few stops too, Apollo Bay is one obvious place and many of the small towns along the coast look the same so keep an eye on the map to find out where you are.
Our motel was right on the main strip of town. This made walking the best option for getting around.