Arguably the most beloved wildlife species in the world, dolphins can be found not just in Sentosa's theme parks but also off urban Singapore.
Wild dolphins are common in the country's congested southern waters, and have been since ancient times, said marine scientists. The trouble is, hardly anybody else knows they are there.
Their presence has gone almost completely unnoticed by the public, baffling scientists at the National University of Singapore's Tropical Marine Science Institute (TMSI), who are trying to raise people's interest and more funds for their work.
In sightings reported to TMSI, at least 169 dolphins were spotted between 2008 and 2011 in the waters between Singapore and Batam, near St John's Island and Pulau Semakau, and as close to shore as Marina Barrage.
At least another 50 were sighted in 2012 - the most recent year that records were kept before TMSI's work was cut short when the conservation fund of Wildlife Reserves Singapore, which runs attractions such as the Singapore Zoo, stopped funding a three-year study by TMSI.
The number of sightings last year and this year has largely remained the same, according to anecdotal reports from scientists.
Dolphins are most regularly spotted in the north-facing bay between St John's and Lazarus islands. The waters there are calm, even during monsoon rains, and there are fishes at the nearby coral reefs, said TMSI's Marine Mammal Research Laboratory head Elizabeth Taylor. She said this could be why the dolphins are attracted to the area, for rest and food, as they swim through the waters around Singapore, Malaysia and Indonesia.
TMSI's Marine Biology and Ecology Lab head Tan Koh Siang said scientists at the institute's laboratory on St John's Island have regularly seen dolphins since 2002, when the lab was established.
Last week, a pod of five Indo-Pacific humpbacked dolphins, also known as pink dolphins, was seen in the waters there by scientists, who posted videos of them on Facebook.
"Even though they are common, for us seeing them in the wild is always exciting... It brings out your inner child and curiosity," said Dr Tan.
Pink dolphins are kept at Underwater World Singapore (UWS). They are the most commonly seen dolphin species in Singapore waters, followed by the Indo-Pacific bottlenose dolphin. There are 23 of the latter species at Resorts World Sentosa (RWS).
In May, a dolphin at RWS died - the fourth death in four years. A dolphin in UWS' collection was reported last month to have skin cancer.
Singapore's wild dolphin population and range is unknown. But Dr Taylor said she is optimistic that their numbers are healthy as sightings of them are "greatly" under-reported. Also, sightings of groups of adult dolphins with calves are common. Dolphins are an apex predator, and this is an indication of the health of the marine environment, she said, as it means they have enough fish to eat.
Dr Lena Chan, director of National Parks Board's National Biodiversity Centre, said: "Indeed, the presence of an animal usually associated with pristine environments is an indication that even in our highly urbanised waters, biodiversity can exist."
Dr Taylor said she plans to use social media to spread the word about Singapore's dolphins.
TMSI also has plans to use drones and underwater listening devices from early next year to survey and track the dolphins round the clock, and is seeking funding for this. Those eager to see wild dolphins can camp overnight on St John's Island, said Dr Taylor, and look out for them at dawn and dusk.