Dark and murky waters surround Pulau Hantu, an island off Singapore's southern coast.
But go deeper - 6m to 16m under, as The Straits Times did on a scuba-diving trip last Saturday - and one discovers a "marine parade".
Bathed in green and yellow, this underwater town is dotted with hard rocks and corals that are branched out like trees.
Shiny fish dart in and out so fast that they appear as slivers of silver - they are the speedsters of the aquatic world.
Like a shy schoolgirl at her first dance, a copper-banded butterfly fish hangs around just long enough to be seen but zooms away when approached.
Farther along the reef, soft corals sway in the underwater current, as though jiving to the music of revving motorboat engines and ship horns. Here, as on land, there is no avoiding heavy traffic.
Despite a name that means Ghost Island, Pulau Hantu is surrounded by life, rich sea life. Likewise, Singapore, the last place people think of when they think nature and wildlife, has plenty of bounty under the sea.
The waters around Singapore are home to more than 250 species of hard corals alone - about 40 per cent of the types of corals found in South-east Asia.
Corals are found not only around Pulau Hantu but also near other islands such as Pulau Sudong, a restricted area used by the military for live firing. Lucky divers get glimpses of sea turtles, dolphins or even reef sharks.
But it is not easy to see what lies beneath.
The waters around Pulau Hantu, for instance, are heavily sedimented, with visibility going only as far as an outstretched arm.
Yet, up until the mid-1960s, Singapore had waters as clear as those at Tioman, said marine conservationist and lawyer Francis Lee, 68.
National University of Singapore (NUS) marine biologist Chou Loke Ming said back then, corals and other reef life at 10m underwater could be seen from a boat.
But as Mr Lee said: "But by the late 1960s, the clarity of the waters went downhill."
Most of the damage was caused by intensive land reclamation and development, he added.
Many people cannot see the splendour of Singapore's underwater life. Professor Chou, who is also principal investigator of the Reef Ecology Lab at NUS, said: "Since visibility is restricted, most people don't see our reef life - it becomes a case of 'out of sight, out of mind'."
Unlike projects today, reclamation works then did not take precautions, such as having barriers around the work site to contain the sediment spread, he added.
When the seabed is stirred up by reclamation, particles become suspended in the water and are abrasive against the soft tissue of the corals.
They also affect visibility, meaning less sunlight pass through the water and less algae grow on the corals. As corals depends largely on algae for food, many slowly died.
Singapore has lost more than 60 per cent of its reef cover as a result.
The good news is that more is being done nowadays. Last month, the authorities announced that Singapore will have its first marine park - a 40ha patch that includes the Sisters' Islands and reefs off nearby St John's Island and Pulau Tekukor.
Coral colonies have also been moved for their protection. In April, the Maritime and Port Authority of Singapore started to relocate 1,600 coral colonies from the south-western Sultan Shoal to waters near St John's island to shield them from the "fallout" from the building of the new Tuas Terminal.
Dive centres and conservation groups here see a growing interest in Singapore's waters.
At local dive company GS-Diving, for instance, the number of participants on their weekly local dive trips have gone up from about eight divers per trip six years ago to about 15 now.
Nature lovers have started groups, like Blue Water Volunteers or Hantu Bloggers, to spread the word about Singapore's marine diversity. The groups often organise diving trips and document the seahorses, sea slugs or other sea creatures they see.
Coral reefs have helped soften the edges of Singapore, often seen as a hard-driving city with scant regard for nature.
Said Ms Debby Ng, founder of the Hantu Bloggers: "(Many think) that there are no coral reefs because much of our coastline is reclaimed, and that living reefs cannot live alongside heavy industry.
"But the fact that we have several living reefs that remain productive around our heavily developed southern coast shows that living reefs and development can find a way to co-exist."