It was hardly diving for treasure, but when 20 volunteers emerged from the waters around Raffles Lighthouse with plastic and glass bottles, ropes and an old tyre, it was a small battle won in the war against sea pollution.
The divers collected 110kg of marine litter during last Saturday's event, organised by the Maritime and Port Authority of Singapore (MPA) to mark World Oceans Day, which falls today.
The rubbish was sorted and brought back to the mainland for proper disposal. Data gathered on the types and sources of marine debris collected will be included in a global survey which hopes to understand and tackle the source of marine pollution.
The divers also organised a second dive to photograph the marine biodiversity in the area.
The National Parks Board and experts from community group Friends of Marine Park will then identify the different species and log them in a biodiversity database. Four categories of marine animals were documented - molluscs, echinoderms (such as sea urchins and sea cucumbers), fish and coral.
Among the volunteers was marine biologist and recreational diver Desmond Ong, 32. He said cleanup dives have gained traction over the past year due to a growing awareness of marine pollution, adding: "I love the environment. This is one way for me to do my part."
He added that there was a "fair bit of trash found" despite the dive site being a relatively untouched area.
"The coral reefs around Raffles Lighthouse are some of the most protected in Singapore.
"They are home to rich marine biodiversity," Mr Ong said.
Mr Andrew Tan, MPA chief executive, said that keeping our waters clean is a shared responsibility. He added: "We can show the world that Singapore can be both a busy port as well as a marine environment rich in biodiversity."
The MPA deploys boats to collect rubbish from ships anchored in the port as well as floating debris along the common channels, fairways and anchorages.
Members of the public can also help during the quarterly Clean-Up on Kayak event, where volunteers remove and sort floating litter.