We're coming to Townsville in early August for 4 day break, managed to get a deal to stay at Rydges hotel. Thinking that we'd want to see Magnetic Island, the aquarium and the Billabong Sanctuary. I'm debating about whether to hire a car. Is it necessary ? Could we rely on cabs to & from airport , and buses if they are available to visits other sites.Many thanks for any local knowledge.