Whitsunday Travel guide for tourism. Travel Guide. The Whitsundays are part of the Cumberland Group that form the largest group of Coastal Islands on the Australian Coast. In total there are 74 islands located right in the centre of the Heritage Listed Great Barrier Reef Marine Park. The Whitsunday group consists of 22 islands, that were named by Captain Cook on his voyage on the Endeavour in 1770. The islands became islands around 10,000 years ago when the Ice Caps melted and the sea level rose around 100 metres. The islands are actually mountain tops cut-off from the mainland by the ocean. Today the islands remain relatively unspoilt, with only eight of the islands having resort style development. The island resorts include Daydream, Hayman, Hamilton, South Molle, Long & Hook. The largest Island, Whitsunday Island only has a viewing platform, signage and a toilet. The Whitsundays provide terrific sailing conditions, with consistent South Easterly breezes and many calm water anchorages nestled among the islands, making overnight stopovers comfortable.