Hienghene

For scuba: verify certification, recent diving experience, medical screening, buddy and guide, functioning gear, oxygen, communications, route selection, maximum depth and whether an apparent tunnel is real overhead. The operator's public site describes boats carrying oxygen, VHF, GPS and a first-aid kit, but that is a published claim, not an independent equipment inspection or guaranteed emergency outcome. Stay within your qualification and no-decompression plan, monitor your dive computer, and respect the skipper's cancellation decision. For snorkeling: use a guide/buddy, assess buoyancy and currents and avoid reefs after significant runoff. For breath-hold training: no dedicated local rescue operation was documented, so never perform solo/deep freediving on an ordinary snorkel boat. DAN's no-fly recommendations apply after scuba even when a flight departs from elsewhere in New Caledonia. Operator information | DAN guidance

Medical support is more limited outside Noumea, and there is no verified local Hienghene hyperbaric chamber. CHT Gaston Bourret at the Medipole in Dumbea is a major hospital. The professional hyperbaric directory lists CHT/SCADEM contacts, while current government travel advice places the documented chamber in Noumea; this does not establish that the chamber is physically at the hospital or ready for an immediate transfer. Treatment availability, destination, transport mode and time-to-care must be determined by medical dispatch. Discuss the actual emergency response and oxygen arrangements with the dive operator, and carry insurance covering scuba, evacuation and repatriation. For suspected decompression illness, stop diving, administer oxygen when trained and available, and contact emergency medical responders urgently; do not self-transport or fly without medical direction. Land emergency medical number: 15. Maritime distress: 16 by telephone or VHF channel 16. Hyperbaric centre | Hospital contacts | Maritime rescue | Regional medical caveat

UNESCO inscribed the Lagoons of New Caledonia in 2008 as a serial property that includes the northeast coast. Province Nord manages protected-area categories and relevant marine wildlife with local customary communities; restrictions vary by designated site. Do not take marine life, handle coral, feed animals, touch turtles or dugongs, or anchor in sensitive reef zones. Before any islet approach, ask the operator whether you may swim, dive, land, kayak or snorkel in that precise area, and whether an additional customary permission is required. The Poule and Sphinx rocks are sacred with an explicit no-landing visitor notice. The unavailable Hienga tour is not permission for independent entry. UNESCO | Province Nord protection | Sacred rocks | Hienga status