Seventy-six sailors from the HTMS Sukhothai have been hauled from the sea after the vessel went down late Sunday roughly 37 kilometres (22 miles) off the country's southeastern coast.

There were 24 personnel still missing, a navy spokesperson said.

Helicopters, two planes, and four ships -- the HTMS Kraburi, HTMS Angthong, HTMS Naresuan and HTMS Bhumibol Adulyadej -- continued searching for survivors on Tuesday.

The bodies of four men were recovered, commander-in-chief of the Royal Thai Navy Choengchai Chomchoengpaet told a press conference in Bangkok.

The navy later revised the toll upwards to five dead.

"We will keep going until the mission is complete and we bring our people back," Choengchai said.

The Sukhothai was carrying extra personnel as it was joining an anniversary celebration of the navy's founder, he said, admitting that there were insufficient life jackets onboard.

"Having a life vest doesn't mean you won't die," he said.

Admiral Chonlathis Navanugraha called the incident "one of the most severe tragedies" in the navy's history.

- Waiting for news -

At a pier in Prachuap Khiri Khan province, anxious families of those missing gathered.

Earlier, they were buoyed by news that Chananyu Gansriya, 23, had been pulled from the water.

Siri Esa, the mother of 21-year-old Saharat Esa who was on board, had a smile on her face when she heard about the latest rescue.

"I also have faith in my son. This is good news," she said.

But Tuesday's waves were still high, navy spokesperson Admiral Pogkrong Montradpalin said, noting the search area had grown and was focusing "on the area near shores, according to the currents and the wind".

Some of those rescued "suffered from broken bones in the upper arm and fingers", Wara Selwattanakul, a doctor with the provincial health department, said.

Phongsri Suksawat, 50, said she hoped that her 22-year-old son Chirawat Toophorm would come home.

"I thought it would be fine and nothing bad would happen from the storm," she said, adding that before her youngest son went on the ship he asked her to take care of his wife.

"I would like to hug him."

- Electrical fault -

The vessel -- a corvette, the smallest type of military warship -- ran into trouble after its electronics system was damaged.

"Crews pumped out the water, but it flowed in quickly, leaving the ship heeling at a 60-degree angle," commander-in-chief Choengchai said at a Bangkok press conference.

While other ships approached to help, he said, the Sukhothai's rear lifted into the air and the ship sank 40 metres down.

When conditions improve, a diving team will inspect the sunken ship, he said, adding that there would be an investigation into the incident.

A warning from the Thai meteorological office remained in place Tuesday, with strong winds causing rough conditions in the Gulf of Thailand. Seafarers were cautioned to be careful, and small boats were advised to stay ashore.

The HTMS Sukhothai was commissioned in 1987 and was built in the United States by the now-defunct Tacoma Boatbuilding Company, according to the US Naval Institute.