This kind of underwater operation usually takes around two hours. After getting out of the chilly water, "my whole body turns numb, and I cannot feel my hands or feet even when you hit them," said Yang.

After going ashore, he would rub his hands and let his body slowly warm up. "Bathing in hot water shortly after getting ashore is harmful for the joints," Yang said.

Yang's first diving experiences date back to 1998. At that time, he was scared by the darkness in the water. But after performing numerous underwater tasks, he overcame the fear and got used to working beneath the water's surface.

Before becoming a frogman, Yang was a clerk in a hydropower station. When the facility required a frogman to shut down a water gate, he volunteered to be trained as a diver.

"I wanted to try new jobs and challenges," Yang recalled.

Yang's mother opposed his decision, worrying about his safety as she thought diving was a dangerous job. But Yang said he enjoys his job, despite all the hardships involved, such as frequently catching colds due to being immersed in cold water for long periods.

After so many years, "I have developed a liking for the job, and I don't want to quit," he said.