Depart from Victoria Point Jetty (Victoria Point, which is about a 35 - 40 minute drive central Brisbane) and head over to Coochiemudlo for the day. There is a ferry which leaves every 30 minutes and costs $4 per person one way. You could take your bike and a picnic lunch, though there is bike hire and cafes on the island. We hired a tandom bike (cannot remember the price.... Take a $50. Should cover it easily!) and rode the whole way around the island. You can also hire kayaks and paddle boats on the island. Swimming is beautiful here, as the water is calm. There is a play ground for the kids, lots of trees for a picnic lunch, fishing spots, walks and other quirky attractions.