Hopes were fading today for a missing British tourist who was onboard a ship with family friends when it sank off the coast of Thailand on Saturday morning.

Rescue teams have spent three days searching for Millie Young, 57, from Brighton, and the diving boat's cook Samniang Chaichana, 67, since they disappeared in rough seas near the Surin Islands archipelago.

Navy chiefs said on Monday that a helicopter and dozens of ships have been following ocean currents in the area around 35 miles from the Thai mainland without finding either the wreckage or any sign of the two women.

Rear Admiral Pongmit Narongkul, Chief of Staff of the 3rd Naval Region, said: 'A navy patrol plane has been flying across the area to search for the two victims along with navy boats.

'An inflatable life raft was found 20 nautical miles from where the ship sank but there was nobody inside.

'The flight path search area has been expanded to the western area of the Surin Islands, with a radius of 15 nautical miles from the forecast point.

‘The missing people have not been found but the search is continuing.'

Millie, an artist and university lecturer, had been on a dream holiday with family friends Jo and Phil Degregorio and their two teenage children Oska and Daisy, who are also from Brighton.

The spinster, who had been splitting her time between Thailand and the UK in recent years, met them at the airport in Bangkok before traveling on their holiday to the beauty spot in the south, where clear water and diverse marine life are a big draw for snorkeling and diving trips.

They booked five places on boat the Reggae Queen and set sail, with the captain ignoring warnings of dangerous sea conditions. The ship was then battered by large waves and took on water around four nautical miles from the enclave of tropical islands.

Officials said a Mayday call was made shortly before 9am. The red, yellow and green boat - painted in the colors of the Rastafari flag - sank shortly after.

Shocked holiday makers scrambled to safety but Millie is understood to have been dragged into the choppy sea along with Samniang, the chef onboard the vessel.

Her shaken British friends were among those rescued when they were pulled aboard a passing fishing trawler. They were pictured with 12 other rescued tourists and four of the crew as they were safely returned to the shore before taking with rescue teams.

The Thai navy along with helicopters and the coast guard are now searching for missing Millie and the Thai woman, a mother-of-two.

Sunee Panpeng, 43, the daughter of the missing cook, said her mother had worked on the trips for around four years, and would have three days at sea before returning to shore.

She added: 'When I was told that the ship had sunk, I was immediately worried about my mother because she cannot swim.

'We can only pray that she will be found. Now I am waiting for a miracle.'

Supoj Rodruang Na Nongkhai, the governor of Phang Nga province, said he had instructed all boats in the area to look out for the two missing people in the Andaman Sea region.

He said that rescued teams were searching in the direction of the sea currents, which are believed to have carried the missing pair in a northwest direction.

The governor added: 'The missing person is a British woman and a Thai member of the crew. We are putting all of our resources into finding them.

'All fishing boats and tourist boats in the area have been instructed to look for the tourists while they are at sea.'

An official from the Phang Nga Provincial Port Security Control Center on Saturday said: 'A notification was received at approximately 9am saying that the ship was sinking four miles south of the Surin Islands.

'The boat was taking tourists on a snorkeling and diving trip. Immediate assistance was provided and 12 tourists were rescued by a passing fishing boat.

'At present, two people are still missing. They are one foreigner and one Thai. One navy vessel and rescue teams are searching the area.'

The Thai Meteorological Department reported that there would be thunderstorms and heavy rain the south west coast of Thailand until December 28.

Conditions at sea during November and December in the south of Thailand are typically the most dangerous of the year, with strong currents, powerful waves and heavy rain.

Ships are understood to have been warned about the dangers and advised to avoid going to sea, due to the conditions.

However, safety on the aging and unregulated vessels is often below standard and operators routinely ignore warnings, swayed instead by the pull of income from holiday makers.

Thai islands have become popular destinations for diving and snorkeling trips because of the clear water and diverse marine life.

Just a day earlier, dozens of passengers were rescued from a sinking ship that was traveling to notorious Thai death island Koh Tao.

Official said 92 tourists were aboard the Sandee Maneesap 111 night boat travelling from Surat Thani province to Koh Tao island when the vessel began taking on water due to a broken pump at dawn on Friday morning, December 22.

One of the worst maritime disasters involving tourists happened in 2018 when a boat carrying more than 120 Chinese tourists capsized and sank in a storm off the resort island of Phuket.

Thirty-three Chinese holidaymakers were killed in the accident.

Thailand typically avoided taking responsibility for its appalling lack of safety and regulation, with the country's then deputy prime minister General Prawit Wongsuwan blaming the Chinese victims.

'This accident was entirely Chinese harming Chinese,' he said at the time.

''The boats were theirs, and they ignored warnings and insisted on sailing out to sea. We weren't responsible for that – they were. They have to resolve this themselves.'