The rickety boat was sighted off the mainland, heading for Koh Yao Yai, a small island that is home to several five-star resorts, between Krabi and Phuket.
Fishing trawlers and a network of small civilian vessels inform local district chiefs of sightings that are usually relayed to Thailand's Department of Disaster Prevention and Mitigation, which oversees safety at sea.
''We think it was definitely a Rohingya boat,'' an official said. ''But we lost contact with it quickly.''
As many as 12,000 members of the Muslim minority in Burma are reported to have fled to sea to avoid persecution since October 15 but only a few hundred have fetched up along Thailand's Andaman Sea coast, alarming activists who fear something has gone amiss.
''Where are they?'' Chris Lewa of the Arakan Project, which plots migration across the Bay of Bengal, told Reuters on Saturday. ''We have become very concerned.''
Back in 2009, Phuketwan journalists discovered that boatloads of Rohingya were being towed out to sea by the Thai military and left without engines or sails. Hundreds perished at sea before survivors washed ashore in India and Indonesia.
Five years on, there is no suggestion of a similar occurrence. But the families of the thousands who are now missing have no clue as to their fate.
Many could be being kept by traffickers in secret jungle camps in mangrove-covered islands along the shores of the Thai provinces of Phang Nga and Ranong, close to the border with Burma, where more than 500 boatpeople from Burma (Myanmar) and Bangladesh have been apprehended in recent weeks.
Almost all of those men, women and children have been taken into custody by local officials, working with Buddhist, Christian and Muslim volunteers to halt the flow of human trafficking victims through Thailand.
With each newly-discovered batch of boatpeople comes an extended debate about whether the unwanted arrivals are human trafficking victims or merely illegal immigrants.
Police and welfare organisations are reluctant to treat the arrivals as trafficked victims because funds and government accommodation are limited.
By categorising the Rohingya as ''Burmese'' under laws that allow Thailand to deal more easily with unwanted arrivals from neighboring Burma, Laos and Cambodia, officials can quickly truck the apprehended groups back to the border where they are often delivered straight into the arms of human traffickers again.
The Rohingya, stateless in Burma, are denied all rights and being driven from Rakhine state by hateful Buddhist neighbors. It's ironic that only as unwanted captives in neighboring Thailand can they achieve their aim of being categorised as Burmese citizens.
Along the coast, district authorities and village chiefs have formed networks among fishing boats to alert them to the presence of boatpeople fleeing Burma and Bangladesh.
Officials from the Department of Special Investigations and the Internal Security Operational Command in Bangkok recently visited the Andaman provinces to assess levels of human trafficking.
Of a boatload of 259 men, women and children who were apprehended near the town of Kaper, 80 Bangladeshis have been sent for processing through a court in Ranong while the other 219 are to be deported as ''Burmese Muslims.''
Burma does not accept the Rohingya as citizens so they cannot return. These people are destined for human traffickers.
Of 86 people being held in the nearby town of Kuraburi, 12 categorised as ''Burmese Muslims'' are being sent to Immigration in Phang Nga while the others, all Bangladeshis, are to appear in Phang Nga court as illegal immigrants.
As trafficking networks grow along the region's Indian Ocean coastline, growing numbers of men from Bangladesh are also being enticed onto boats in search of better jobs in Malaysia.
Bangladeshi authorities are holding five Thais who have been accused of human trafficking and other arrests have been made in Thailand.
September 23 37 boat people at Takaupa, categorised as illegal immigrants. Sentenced to 20 days in jail, now held by Immigration for deportation
October 11 53 boatpeople at Takaupa, categorised as victims of human trafficking, held in shelters at Ranong, Songkhla and Phang Nga
October 13 81 boatpeople at Takaupa, categorised as victims of human trafficking, held in shelters at Ranong, Songkhla and Phang Nga
October 24 boatpeople at Suksamran, categorised as illegal immigrants, sent to Ranong Immigration
October 78 boatpeople at Suksamran, Twelve ''Burmese Muslims'' sent to Ranong Immigration, Bangladeshis passed to court system
November 8 299 (overnight suddenly reduced to 259) boatpeople at Kaper. 80 Bangladeshis sent Ranong court, 179 ''Burmese Muslims'' at Ranong Immigration
November 11 86 boat people at Kuraburi, 12 ''Burmese Muslims'' to Phang Nga Immigration, Bangladeshis to Phang Nga court