Abyss Scuba Diving is at the centre of Sydney's best scuba diving and has the aim of maximizing your diving fun. Sydney has excellent diving, which is unequalled by any large city throughout the world. Sydney has more marine species than any other harbour in the world with more 600 marine animals have already been identified. One of the great attractions of diving around Sydney is its abundant sea life offering such unique critters as the weedy seadragon.