“Noting the time since the 27 people went missing and from previous experience … The chances of finding them alive are very, very slim,” said West Wu Wai-hung, a controller from the flying service.

“Our hearts are with the families of the missing sailors and workers, and I do wish we find some survivors. It will be a miracle to do that.”

Hong Kong issues No 3 typhoon signal as President Xi Jinping visits city

Wu vowed the flying service would continue to do its best to locate the missing seamen, but bad weather had been hindering efforts.

He said the rescue mission had to be paused after nightfall on Saturday as conditions were still bad even after the typhoon signal was lowered to No 3, and continuous search-and-rescue operations would have made it dangerous for the crew.

He also said the safety of the crew was paramount to the operation, and his team had to make “in-depth assessments” on weather conditions to form contingency plans.

01:16

Dramatic rescue after Typhoon Chaba snaps ship in two off coast of southern China

Dramatic rescue after Typhoon Chaba snaps ship in two off coast of southern China

Karl Chan Ka-to, a senior helicopter training captain who joined the mission, said it was challenging to deploy aircraft to the site due to strong winds.

With wind speeds consistently at 90km/h and sometimes hitting 140km/h, Chan said aircraft in the area faced heavy turbulence and “shook all the time”.

He added that calculating fuel usage was also tough because of difficult conditions and unfamiliarity with the environment.

“The wind changes with the typhoon, whenever we calculate [the fuel amount] it will not be accurate, so we had to bring extra supply,” Chan said, adding that rescuers would remove “unnecessary items” from aircraft before deployment to reduce weight and fuel usage.

Typhoon Chaba: Hong Kong’s No 3 warning signal downgraded to No 1

For another rescuer Cyrus Szeto, the choppy sea meant his team had to think fast when attempting to rescue the three men.

The aircrew officer said the ship was already split into two when emergency teams arrived, and the three men were holding tight to railings of the tilted vessel while battered by waves up to 10 metres high.

“Normally we rescue people one by one, as it’s safer. But in that situation, it was difficult to wait, so we had to make a decision to rescue two at a time,” Szeto said. “The two seamen were not seriously injured, and we quickly went on to save the third person, as we were worried he was running out of time.”

He added there was no stable landing spot as rescuers lowered themselves from the helicopter. “If we waited one more minute, those three men may have been washed away,” Szeto said.

Chief Secretary Eric Chan Kwok-ki on Sunday said he was saddened by the mishap and had instructed the Security Bureau, alongside the Government Flying Service and other relevant agencies, to race against time to find the missing crew members.

The Office of State Flood Control and Drought Relief Headquarters and the Ministry of Emergency Management said after a meeting on Sunday the incident had exposed weaknesses in typhoon preparations.

They said all possible efforts should be made in the search for the missing crew members and called for lessons to be learned from the incident to prevent a repeat.

An immediate investigation into what happened should be launched, they added.