I was engaged in several years of prolific travel around the world, identifying candidates for development as diving destinations. During that year, I did an exploratory to Vanuatu and nearby New Caledonia.
The treasure I found in New Caledonia was a small island off the southern tip of the main island, a paradise called Ile des Pins, or the Isle of Pines. There were in fact pine trees everywhere, a placid lagoon of exquisite beauty, and deep in a wooded area, the entrance to an underground cavern filled with clear water known as The Grotto.
This was heady stuff, but getting divers there would be expensive and the logistics formidable, so it wasn't possible to offer it on a regular basis.
A decade later, I found a 140-foot cruiser that we used for several years to dive Vanuatu from one end to the other. For two years, we also offered a Grand Tour which included both a week in Vanuatu and a voyage to New Caledonia via the Loyalty Islands. In the Loyalties, we found friendly natives, exquisite reef diving in brisk currents and even some good shark spots. We also found a treasure trove of the Merlot's Scorpionfish, Rhinopias aphanes. The little rascals were everywhere.
Sadly, the big boat wasn't able to generate the huge volumes to support itself (the islands had rather short good-weather seasons) and finally went out of business. This is one of many examples of what I call The Golden Age of Diving Exploration, when we had a number of these colossal adventures that never turned into mass-market success and disappeared.
While they were running, though, they were nothing short of sublime...