Prony Harbor is divided into several smaller bays, and onshore, the ruins of an old penitentiary building can be seen, along with the remnants of old iron ore mining operations. Beautiful banyan forests and hot springs add charm to the area, and offshore, minerals from those same hot springs have built up a tall pinnacle called the Prony Needle. An incredible place to dive day or night, the needle is easily accessible to all divers.
Geology
Unlike many other pinnacles, this incredible spire is continually formed as minerals from the hot springs make contact with cooler, salty sea water. Geologists have found the needle to be composed of Brucite, Burbankite, Calcium, and Aragonite. The Prony Needle rises up from the sludge covered ocean floor at a depth of 40 meters, only missing the surface by two meters. Shaped like a huge pyramid, and covered in a myriad of smaller outcroppings, including one famous formation called “The Cathedral,” the needle invites close inspection and thorough investigation. Its top features a surface area of just four square meters.
Diving Prony Needle
The usual dive profile calls for a descent to about 25 meters, followed by a leisurely journey back up and around the needle. Covered in masses of coral and sheathed in a layer of oysters and other bivalves, the site is awe-inspiring and is teeming with marine life. You’ll find lots of scorpion fish and groupers, along with lots of macro life. Necklace sea stars, with their mosaics of white contrasting with brilliant flame-red bodies, nudibranchs in a wide array of colors, harlequin shrimps, and tiny cowries captivate the imagination.
Reef fish are everywhere; in every color of the rainbow from the cerulean blue and bright yellow of the emperor angelfish to the tangerine and lemon of the Eclipse Pigfish, with its telltale patch of black near the tail. Keep one eye on the blue; there are schooling jacks and trevally, lots of snapper, and the occasional passing flight of manta rays or pair of reef sharks. Barracuda are often encountered here, as well.
On night dives, Spanish Dancers flourish and flounce their way along the structure, while crustaceans exhibit more activity than they do during the daytime. Corals extend themselves to feed, and if you are very lucky, you may even catch a glimpse of the Pearly Nautilus, which comes up from out of the abyss to prey on sleeping fish and other shallow water creatures.
In December, groupers spawn at the needle, attracting the attention of fishermen; be careful of lost fishing line and hooks as you explore, and carry a sharp knife so you can free any creatures that may be trapped. Between July and September, you may encounter humpback whales as you make the two-hour boat ride from the mainland. A trip to Prony Needle can be arranged with nearby dive operators, who also offer side excursions up the nearby river and onto nearby historical sites. As this is an in-demand location, it is important to plan well in advance to ensure you can visit when you come to New Caledonia. Bring your camera, and prepare to be astonished.