Underwater World was Sentosa's star — then a bigger aquarium opened next door

Underwater World opened on Sentosa on 13 May 1991 — a $20 million oceanarium built around an 83-metre acrylic observation tunnel with a travelator gliding through three million litres of filtered sea water. More than 2,500 marine animals of 250 species lived there, and a Dolphin Lagoon added in 1999 housed rare pink Indo-Pacific humpbacked dolphins. It drew a million visitors in its first year and became one of Singapore's signature attractions.

The island changed around it. Resorts World Sentosa opened Universal Studios Singapore in 2010 and the vast S.E.A. Aquarium in 2012; visitorship dwindled, and analysts began calling Underwater World a 'micro attraction' next to the new integrated resort. With the lease on the Sentosa site due to expire within two years, operator Haw Par Corporation saw no case for reinvesting.

Haw Par announced the closure on 6 June 2016; the doors shut early, on 26 June, to give time to move the animals. About 160,000 people came in the final weeks. After nearly a year searching for new homes, the pink dolphins, fur seals and otters went to Chimelong Ocean Kingdom in Zhuhai — chosen because the Pearl River estuary nearby is the dolphins' native habitat. Haw Par's sister park in Pattaya, Thailand, kept operating.