The Quarry is a section of north coast reef which, although only meters from the shore, drops off to over two thousand feet at a near vertical angle.

Swimming out over the reef you can identify many species of "dendrophyllid corals"; especially giant barrel shaped "Turbinaria Frondens". Some are over a meter in diameter. These are surrounded by a dazzling array of colonies of "golden Daisy" or "Sunshine Coral" - "Tubastraea Aurea", which cling precariously to overhangs and the walls of small caves located in the reef wall. There is always the opportunity for photographing the beautiful "nudibranch mollusc" "Phestilla Melanobrachia" which seems to consider the aurea its staple diet. The aurea is also eaten by the "Wentletrap Snail", which eats out the polyps and leaves strings of bright yellow eggs in the cavities. The shallow water on top of the reef and its crystal clarity make this an ideal option for even the ambient light photographer.

The ecosystem of The Quarry also seems particularly favourable for virtually every other species of marine mollusc. Although classified by the anatomy of the animals living within them, the vast range of univalve shells found around The Quarry area have some very descriptive common names. Here have been found "Tiger Cowries" and even the prized "Golden Cowrie". Numerous "Spindle Cowries" can be seen feeding on "Gorgonias" and soft corals. Also to be found are the full range of "Olive Shells", "Strombs" and "cones".

Lucky divers have even witnessed a "Charonia Tritonais", the rare "Giant Trition", over fifty centimeters in length consuming a "Crown-of-Thorns" starfish here. Unfortunately the bustling tourist trade in Madang sees a number of these fast disappearing "Tritons" on sale at local markets. The villagers along the North Coast seem more farsighted, however, and refuse to have any shells removed from the reefs in their area.

Besides the mollusc and corals, the other main attraction at The Quarry, are large sharks, which inevitably follow the ocean currents that flow past the reef wall. Silver Tips are commonly seen here their thick, barrel like torsos distinguishing them from the more sleek reef sharks which are more common along the barrier reef. You may also have the opportunity of comparing the Oceanic White Tip, that occasionally appears here with its smaller cousin, the Reef White Tip.

The current at The Quarry is strong and unpredictable, in that its direction can vary according to the depth - it is possible at times to drift dive south at 100 feet and then ascend to 60 feet and drift dive back to the north.