The HTMS Kraburi sails out from Prachuap Khiri Khan on Tuesday to resume the search for survivors after the sinking of Thai naval vessel HTMS Sukhothai.

Rescuers in helicopters scoured the Gulf of Thailand on Tuesday (Dec 20) for dozens of sailors who went missing when their naval vessel sank, hoping life jackets had helped them survive two nights in the choppy waters.

Seventy-six sailors from the HTMS Sukhothai were hauled from the sea after the vessel went down late Sunday in the Gulf of Thailand, roughly 37km off the Southeast Asian country's southeastern coast.

Thai warship the HTMS Kraburi left port to resume the search early Tuesday, scanning the turbulent waters for 30 missing sailors alongside other naval vessels and two Seahawk helicopters.

"I am hopeful we will find some survivors, because they have life vests," said naval officer Narong Khumburi.

Efforts to find the missing crew were focused on aerial searches, with the Royal Thai airforce assisting the operation.

HTMS Kraburi commander Kraiwit Kornraweeprapapitch said slightly improved weather would help the search.

"The format of searching is still the same, which is a joint operation with helicopters," he said.

"The format of searching is still the same, which is a joint operation with helicopters," he said.