The mechanic: Wang Dong, 33

I was born in Nanchong in the east of Sichuan province in 1986. When I was young, I thought it was cool to be a soldier, so I joined the People's Armed Police Force at age 18.

As a teenager, I was fascinated by machinery and was always dismantling and assembling simple devices. So, when I was offered the chance to attend a military academy to study mechanical and electrical engineering, I agreed and passed the entrance exam easily.

After two years, I graduated from the academy and was dispatched to the vehicle repair unit of the border defense force in Yunnan. I spent eight years in the unit, and grasped the principles of vehicle maintenance and repair so well that I could identify problems just by listening to a faulty vehicle.

In August 2016, I was transferred to the border patrol. Some of the senior officers told me that I might have to take part in the joint patrols on the Mekong River. I realized that they wanted me there because of my engineering background, so I prepared by reading books about ship repairs and maintenance.

However, when I was on board and started a five-day patrol on the river, I found it hard to put the things I had learned into use because whenever there was a technical malfunction on the ship, it always seemed to happen in unexpected situations that required experience more than technical knowledge.

On a joint patrol a few years ago, our ship stopped moving during a night crossing of the China-Laos border. I thought the cause could be an engine problem or a technical error, but after checking for a few hours, I could not find any faults. We had to wait for help.

The next morning, a ship came to help us, and as we were towed free we discovered that our ship had simply been wedged between submerged rocks. It was then that I realized why my captain said that the best compliment for a technician is to be called "professional" and "experienced".

I think I am close to earning that kind of compliment, having taken part in many patrols and solved different problems. But now, I would rather be a qualified father as I am too busy to be with my two children and can only spend one month a year with them.