Those GBR tours are the same operators for Royal, P&O etc . The outer reef is along way out so the CAT's come to the ship ,which is a tender stop At Arlie beach, to make it a possible day trip. They will sell out . Tangalooma wrecks , you can walk up the beach to and use your own goggles. Willis is you will be snorkelling in the pool ,its a sail /bye 🤣👋.Tangalooma Wrecks