As strong winds and choppy waters buffeted their kayak near Mersing, Johor, two Singaporeans found themselves drifting further away from a group of 13 other Singaporeans taking advantage of the long weekend for a trip up north.
Experts said Mr Tan Eng Soon, 62, and Madam Puah Geok Tin, 57, are likely experienced kayakers and may have attained the necessary certification for rowing in open sea.
But the conditions around the Endau islands were rough at about 5.40pm on Thursday when they went missing.
Members of the group tried to search for them but had to give up after making no headway, media reports said. They made a police report at the Rompin police station in Pahang at 10.30am on Friday.
Shin Min Daily News spoke to Madam Puah's husband - 59-year-old retiree Pang Wenjie - yesterday.
He said his wife and Mr Tan did not know each other before the trip, but were paired on the same bright green kayak.
The Sunday Times understands that Madam Puah is a businesswoman, and in 2000, owned a business providing swimming lessons.
Mr Pang said they have two adult children who are in their mid-20s. The older, a daughter, works in Australia. Their son was a participant in the National Day Parade (NDP) on Friday, and learnt of his mother's disappearance only when he got home that night.
He has since joined his father in Malaysia and they were understood to be keeping vigil in the vicinity of the Penyabong jetty in Endau, Johor. Mr Tan's family is also believed to be there.
Singapore officials are also on the ground to provide assistance and support as search operations widened yesterday.
Based on wind direction and water currents, the search and rescue operations are moving northwards from the site where the two were last seen, Mersing district's acting police chief, Assistant Superintendent Mohd Nor Mohd Isa, told The Sunday Times yesterday.
A team of 41 people has been mobilised in the search operation. The authorities have also deployed an aircraft and six boats to look for the missing pair.
According to updates from the Malaysian Maritime Enforcement Agency (MMEA), the air search has been expanded to 400 nautical miles north of Pulau Seri Buat to north-west of Pulau Tioman. The sea search on day two covered 150 nautical miles from Tanjung Resang, Mersing to Kuala Rompin, Pahang.
Despite cloud cover and light rain yesterday, the search and rescue operation proceeded until 7pm.
MMEA officials in Johor said the Johor Baru marine rescue sub-centre was notified of the two missing tourists at about 2.15pm on Friday. A search and rescue team was activated at Penyabong jetty at about 3.30pm on Friday, the Malaysian officials said.
Singapore's Ministry of Foreign Affairs (MFA) said yesterday that the Singapore Consulate-General in Johor Baru has been in close contact with the Malaysian authorities who are coordinating the search operations.
"MFA and the Consulate-General will continue to render consular assistance to the next of kin of the missing Singaporeans and support the ongoing search operations," the statement said.