Hippolyte Rocks
The waters surrounding the islands, including the nearby Trident Reef, are part of the Great Southern Reef, and have been described as being the best, though among the most challenging, dive sites in Tasmania. There are two shipwrecks between the Hippolytes, including the 1883 Tasman, which lies at a depth of 70 metres, and the 1915 Nord, which lies at a depth of 40 metres.
Fauna
Recorded breeding seabird species are little penguin, short-tailed shearwater, sooty shearwater, fairy prion, common diving-petrel, silver gull and black-faced cormorant. Australian fur seals use the island as a haul-out site. The metallic skink is present. Together, Hippolyte rocks and the nearby Thumbs have been identified by BirdLife International as an Important Bird Area (IBA) because they support over 1% of the world population of black-faced cormorants.