Used the Hop on Hop Off Ferry for Two days. In hindsight, for us one would have been enough. We started a Circular Quay then stops to Taronga Zoo, Shark Island (no amenities, bring what you need), Watson Bay and Manly Beach. It was a beautiful 2nd day so we just stayed on the boat for a complete loop. Staff was pleasant and helpful. Safety conscious and clean. Bathrooms aboard if needed. Enjoy!