The HTMS Sukhothai sank on Sunday night with 105 crew on board. Photo: Twitter / Royal Thai Navy
Rescuers have recovered the bodies of six crew members from a Thai warship that sank off the country's south-east coast, the navy has said.
The dead sailors and one survivor were found on Tuesday as military teams scoured waters in the Gulf of Thailand.
A search is continuing for 23 sailors still missing. The navy says 76 crew members have been rescued in total.
The HTMS Sukhothai went down on Sunday night with 105 crew on board after losing power in a storm.
The Thai navy and air force have spent two days searching for survivors, with hundreds of officers on four navy ships as well as several helicopters and unmanned drones deployed to scan a 50sq/km area of ocean.
"The latest person was found 41 hours from when the ship sank and he was alive. So we believe that there are those still alive out there... we will continue to search," said Admiral Chonlathis Navanugraha, the navy's chief of staff.
A naval commander had earlier suggested search crews had only a two-day window to find anyone alive, given the time they had spent in the ocean.
Several sailors have already been found, exhausted and unconscious in some cases. Not all of those missing are wearing life vests.
"We found this guy holding a life buoy... he was floating in the water for 10 hours," Captain Krapich Korawee-Paparwit of the HTMS Kraburi told Reuters.
He added that the man, still conscious, had a minor head wound and "sore eyes as he was exposed to sea water."
A sailor who survived the sinking is carried on a stretcher at U-Tapao Royal Thai Navy Airfield in Rayong Province, Thailand. Several survivors have been found, exhausted and unconscious in some cases. Photo: AFP / Handout / Royal Thai Navy
Other sailors were found in a life raft after they jumped from the sinking vessel. Pictures and footage shared by the navy on Twitter show survivors wrapped in blankets and being taken to hospital.
Navy officials initially said 106 people were on board the ship, but revised that number to 105 on Tuesday.
The HTMS Sukhothai, a 76m corvette, had been on day two of a routine patrol when it went down. The navy said water flooded its hull and then the electricity room, cutting the power.
Dramatic pictures posted on the navy's Twitter account show the vessel listing onto its starboard side, before it went under around 23:30 local time on Sunday.
Other naval ships were immediately alerted and sent to assist, but only the HTMS Kraburi frigate reached the boat before it sank, about 32km east of Bang Saphan in Prachuap Khiri Khan province.
It is not yet known what caused the ship to flood, and why sailors were forced to jump into the water.
The Thai navy said this was the first time it had lost a vessel in such circumstances, and it would launch an investigation.
However, naval experts have questioned how such a disaster struck a ship on a routine patrol.
"It's really unusual," said naval law expert David Letts, an associate professor at the Australian National University.
He noted there were measures to prevent flooding affecting central units like the engine room.
"The ship's divided into compartments - and there should be a series of watertight doors that start on the upper deck, so the ocean doesn't get down into the ship itself."
The fact the disaster struck at night meant it was probable many sailors would have been asleep at the time, and the chaotic situation might have upended protocols like getting crew to upper decks or releasing life rafts.
The warship had been commissioned in 1987 and built in the United States by a local shipbuilding company, the US Naval Institute said.