Search-and-rescue operations for undergraduate Goh Chuan Kiet entered the third night on Tuesday after his disappearance in the sea off Changi.
The 23-year-old Singaporean went missing on Sunday afternoon. At the time, he was paddle- boarding with his schoolmates from SIM Global Education's windsurfing club when thundery showers hit the area near Tanah Merah Ferry Terminal, with winds gusting up to 22 to 25 knots along the coast.
The board and paddle he was using were retrieved by rescuers and fishermen within the day, but there were still no signs of Mr Goh as of last night.
The Maritime and Port Authority of Singapore released a statement on Tuesday evening saying it would continue rescue efforts with the Police Coast Guard and National Service Resort and Country Club, from which Mr Goh had set out on Sunday.
A SIM Global Education spokesman told The Straits Times that the students' outing was not organised by the school, and that "paddle-boarding was not part of the official activities of the club".
Over the past two years, the sport of stand-up paddling (SUP), a form of paddle-boarding, has gained popularity in Singapore. It involves standing on a board while using a paddle for direction and speed.
But there are no mandated safety guidelines or required certifications for the sport, even when it is practised in open water.
This is unlike its close cousin, kayaking, for which two levels of certification are required before one can enter open water for long trips.
The Straits Times understands that Mr Goh, who passed his Level One windsurfing certification less than two weeks ago, was using a friend's paddle-boarding equipment at the time.