By Nick Squires
BBC, South Pacific
Sixty years on from World War II, an act of environmental vandalism is proving to be a valuable asset for the tiny South Pacific nation of Vanuatu.
Scattered on the seabed is what looks like the shattered remains of a phantom army.
Peering through my diver's mask at first I could make out little more than ghostly shapes.
USS President Coolidge was a liner before becoming a troop ship
But as I descended deeper into the green-tinged gloom, a bizarre sight unfolded before me.
Resting on the seabed were military trucks, up-ended jeeps, and powerful-looking army bulldozers.
There were twisted metal girders and rubber tyres, their treads still clearly visible.
Half buried in the sand I found a vintage Coca-Cola bottle. I dug it out and slipped it into my wetsuit as a souvenir.
This is Million Dollar Point, one of the world's most unusual diving spots.
It is a vast undersea junkyard lying just a few metres off a pristine white beach on the island of Espiritu Santo in the South Pacific nation of Vanuatu. How it came to be here is one of the stranger stories of World War II.
Before independence Vanuatu was an obscure Anglo-French territory known as the New Hebrides.
From 1942 it became the focus of a massive military build-up by the Americans.
Half a million or more US troops poured into the tiny colony in preparation for the great counter-offensive against the Japanese.
Coconut plantations were cleared, local men were recruited as porters, and the sleepy colonial outposts of Port Vila and Luganville were transformed into bustling military hubs.
Once the war was won, the Americans were faced with the problem of what to do with all the military material they had accumulated.
The high cost of shipping made it too expensive to send back to the States.
So the Americans offered to sell much of the equipment to the French and British.
But the colonial authorities calculated that the Americans would have to leave everything behind anyway, so why pay for it?
Their bluff failed in spectacular fashion.
In a fit of pique, the Americans decided to dump immense quantities of supplies instead of giving them away for free.
Navy engineers known as Seabees built a jetty and simply drove the unwanted Jeeps, trucks, and bulldozers into the sea.
World War Two relics can be found on many Pacific Islands
Sixty years on these weapons of war have become a remarkably rich artificial reef. The abandoned vehicles are encrusted with vivid red and yellow corals.
I swam idly past a bulldozer and noticed a pink and blue shrimp perched delicately on the driver's metal seat, where once a GI would have sat.
The barrel of an enormous naval gun was inhabited by a cluster of clams.
As a couple of flipper kicks took me ever deeper, a lionfish emerged from behind a rusted axle.
An enduring legacy of mankind's most deadly conflict, Million Dollar Point is now an asset to Vanuatu, attracting divers from all over the world.
Many of them take in an equally spectacular dive site a little way along the coast.
The USS President Coolidge was a luxury liner when it was converted into a troop ship at the outbreak of war.
In 1942 it was carrying 5,000 men when it accidentally hit two American mines.
The quick-thinking captain managed to ground it on a reef, allowing all but two of its officers and men to wade ashore.
An hour later, it slid beneath the waves and is now one of the most acclaimed wreck dives in the world.
Those who venture into its flooded decks and cargo holds encounter a weird mixture of civilian luxury - chandeliers, a tiled swimming pool - and raw military necessity, including gas masks and ammunition.
It is not just Vanuatu that is benefiting from the detritus of war.
In Papua New Guinea a guide led me into a patch of jungle which was once a Japanese military airfield.
Lying crumpled amid the luxuriant foliage was a Japanese bomber, its ribbed fuselage and skull-like nose cone resembling the skeleton of some great prehistoric beast. Bullet holes showed where it had been attacked by Allied fighter planes as it struggled to take off from the long-forgotten tropical airstrip.
In the neighbouring Solomon Islands, one sea channel is so littered with sunken American and Japanese warships that it is known as Ironbottom Sound.
Hellcat fighter planes sit on the ocean floor, their machine guns silenced forever. Where once they were strafed by Japanese Zeros, now they are circled by sharks.
Machines designed to take life have instead spawned new life in the South Pacific.
Million Dollar Point may be an indictment of the appalling wastefulness of war. But it has become one of Vanuatu's best known attractions. As such it needs to be preserved just as it is.
As I shrugged off my air tank at the end of the dive, I reached into my wetsuit and threw that scavenged Coke bottle back into the sea. Keeping it just did not seem right.
Even underwater junkyards deserve some respect.
From Our Own Correspondent was broadcast on Thursday 31 January, 2008 at 1100 GMT on BBC Radio 4. Please check the programme schedules for World Service transmission times.