u/lettucequestionmark

Hi everyone! My friend and I are going to be staying in cairns this upcoming summer, at a hotel in the city/main downtown area. I was wondering if there would be enough to do close by/in reasonable walking or uber distance in order to fill a 5 day itinerary? My friend and I are both under 21 and therefore at the car rental places will be charged extra for insurance etc or just not be allowed to rent cars at all, so we are wondering if it is worth it to go without access to a car? If so, all recommendations would be greatly appreciated :) we are especially interested in great barrier reef tours so it would be great to know if some were avaliable close to the city. Thanks everyone!