A regular patrol came alongside the vessel about nine miles north of the Thai island of Surin about 5pm yesterday, Phuketwan was told.
''Those on board were given food and water and medical assistance,'' the source said, ''as human rights require.''
Thailand's ''help on'' policy was introduced to replace the ''pushbacks'' campaign, introduced in secrecy, which led to the deaths of hundreds of boatpeople in the sailing season of 2008-2009.
Under the ''help on'' policy, the Thai Navy and onshore paramilitary volunteers intercept the Rohingya boats in open waters to provide passengers with food, water, medical assistance and mechanic help if required. But they will not allow the boats to land in Thailand.
With the end of the monsoons and the arrival of the safe sailing season that usually lasts until April, a greater number of Rohingya than ever before are expected to put to sea in the next few weeks.
The Rohingya men and boys who take to the boats will be seeking a new life and sanctuary because of the ethnic cleansing now taking place in Burma, also known as Myanmar.
There was a time when the Rohingya hoped that Burma's new openness and the freeing of Aung San Suu Kyi would end their plight, so they stayed ashore.
As Burma's new government lifted restrictions, what actually happened was the opposite of what the Rohingya had hoped.
Their neighbors in Rakhine state used the new openness to denounce the Rohingya and burn their villages. Scores of Rohingya have been killed and thousands of homes razed in two waves of ethnic cleansing, the first in June and the second this week.
Some of them were forced to flee in boats. Others will be doing the same soon, probably by the thousands, heading south past the holiday island of Phuket to what they hope will be a haven in Malaysia.
Almost 5000 Rohingya came ashore in Thailand in the sailing season of 2007-2008, a nuisance for Thai authorities that led to the secretive and deadly ''pushbacks'' in the following season.
The boat that was intercepted yesterday is expected to be perhaps the first of many. Most of the boats have in the past sailed from Cox's Bazaar in neighboring Bangladesh.
Now the game has changed. The latest repression is likely to produce departures from much further south, with more desperate people taking more desperate options.
Where once the would-be refugees fled in ricketty old vessels that were often barely capable of staying afloat, of late many Rohingya men and boys have opted to catch small boats out to sea, where they join larger boats.
That way, more of them are able to avoid Burmese navy vessels. Perhaps 12 ''ferries,'' as they are called, may leave ports along the coast.
Perhaps two may be stopped, with perhaps 10 reaching a rendezvous point. With as many as 300 on board a small cargo vessel, the journey south is much faster and safer.
In past sailing seasons, emaciated passengers by the hundreds have come ashore north and south of Phuket or on the famous holiday island, most often because they run out of food and water.
Bangladesh rejects the Rohingya, Thailand helps them on, and most of the world ignores their plight. With torched villages, open displacement camps and hatred at their backs, it's little wonder that the Rohingya are prepared to take enormous risks.