WEDGED between the Shell oil refinery and three islands used by Singapore's air force for target practice, Pulau Hantu is not quite the tropical idyll one expects in south-east Asia.
It is certainly not one of the premier destinations for scuba divers, who tend to travel to Malaysia rather than explore the tiny islands and reefs that surround Singapore.
But Pulau Hantu is a quick 20-minute motorboat ride from Keppel Bay, home to Daniel Libeskind's latest architectural wonder - a series of skyscrapers that bend towards the sun like palm trees.
There are countless reasons why divers don't plunge into Singapore's warm waters, not least of which is that you're likely to see more diving into a vat of Guinness, says expat dive instructor Gary, who gave up his day job as a logistics manager for a life in neoprene instead.
The deafening roar of fighter jets breaking the sound barrier isn't exactly welcoming either, especially the one that zeroes in on Anjolie, the tiny three-metre boat that George, an Englishman with a porn star's moustache, has anchored next to the island's lagoon.
A stingray flaps past like a bed sheet.
In the distance are the fun park rides of Sentosa Island and queues of rusting freighters waiting to unload their cargo to satiate Singapore's relentless consumers.
The island's history isn't exactly welcoming - hantu is the Malay word for ghost and apparently the island is full of the spirits of Malay warriors who found themselves on the wrong end of a duel. A more prosaic reason for the name might be because the island is partly submerged at high tide.
It was also a notorious graveyard for divers during the monsoon, Gary says, adding to the list of reasons I should have stuck to Singapore's main drawcard of shopping.
But the storm clouds are replaced by brilliant sunshine as I wriggle into my diving vest and flippers, check my oxygen tanks and hawk a mouthful of spit into my mask to clean it.
Gary even reckons we may encounter the island's other famous resident, the hawksbill turtle, so-named because its pointy head looks like a bird's beak.
I'd be happy to meet anything other than an oil slick as I perform a graceless backflip off the boat, into the brackish but reasonably clear waters.
Gary gives me a quick nod and a thumbs down, which in the sign language of diving means descend, and we leave the noisy, crowded surface for the serenity of the water below.
Diving is a lazy person's pastime where the less you move the slower you breathe and the longer you can stay submerged.
Despite its proximity to Singapore's bustling port, the reef look surprisingly healthy with an abundance of mushroom coral, which has the handy ability to change sex.
Besides gender-bending coral, a stingray flaps past like a bed sheet as well as clown fish, wrasse and a school of zebra-striped horrors that follow behind me like a pack of starving dogs.
One of the many pleasures of diving is being able to wee in front of other people without risk of social ostracism (emptying the bladder also conserves body heat).
Eventually the oxygen gauge ticks towards the red danger section and we slowly ascend to the surface to be greeted by a fighter plane streaking past us, its gun sight no doubt trained on our flippers.