Reporter's Log: Finding my sea legs while inspecting troubled waters

I was ecstatic as the ship approached the bank of the Pearl River. The mere sight of land and the expectation of standing on it again were so thrilling.

This is how I felt after spending 16 days on board a ship where everything was on the move and undulating.

But when I stood on dry land again, the moving sensation didn't stop. I had to learn how to walk again after completing a 3,300-nautical-mile (6,100-km) journey on the South China Sea.

The journey started on March 5, when two vessels of the China Marine Surveillance set out from the southern port city of Guangzhou on the third patrol this year, targeting the illegal exploration of oil and gas. I was on the 3,000-ton Haijian 83, the larger of the two ships.

As the ship sailed south, murky costal waters became green, and within half a day all I could see while standing on deck was boundless blue water. In the following days, the ships passed the waters of China's Xisha and Nansha Islands, and went as far as the shoal of Zengmu Ansha, the southernmost point of China's territory.

Haijian 83 has a crew of about 40, working mainly as deckhands or in the engine room.

The ship is equipped with the latest technology, which lessens the burden of duties on board, but the working environment is still harsh.

Those working on the ship's bridge, the control center, suffer more from the effects of the sea's swell and waves, being highest placed on the vessel, while those in the engine room, below the surface, have more stability but work in constant noise and heat.

Every morning the CMS' law enforcement officers come to the bridge to check the radar display screen to see if any illegal oil rigs had appeared in Chinese territorial waters.

Most oil rigs have several floors, and some burn off gas, shooting flames so high into the sky that they can be seen miles away, even in intense tropical sunlight.

Investigating these rigs is the busiest moment for all on the bridge. One officer sits in front of the radar screen, noting the distance and direction of the rigs. Another observes a different screen and records the ownership of the rigs, and is in radio contact with them. A CMS interpreter stands by to translate. The captain supervises operations, waiting to discover whether the rigs are authorized to drill.

The captain believes the number of oil rigs operating illegally in Chinese territorial waters is "enormous".

The South China Sea branch of State Oceanic Administration issued a notice saying more than 30 foreign oil rigs were spotted along the route of our patrol alone.

Usually, CMS officers only take photographs and make a record, and the ships sail past the rigs without disrupting their operation.

As we sailed south, more and more rigs appeared. At one time, I counted eight in the sea around us, some only a mile apart from others.

When we sailed close to one after dusk, the giant platform, beaming golden light, dwarfed our vessel and lit up the sea around us.

And that was as exciting as it got. At least we were spared the dramatic events of rough seas and the utter despair of seasickness, which defeats even the most seasoned of seamen.

I was lucky. The sea remained calm most of the time. The captain told me it was the best time of the year for a sea voyage, as we had missed the cold fronts from north, and the typhoon season was not yet upon us.

However, just as I was counting my blessings near the end of the voyage, the sea swelled in power and rocked our boat. I spent a terrible night vomiting and getting no sleep.

As I was returning to Beijing, happy and relieved, I also felt a sense of loss after saying goodbye to those with whom I had spent 16 days.

They are a special group, living a different life from most of us, and almost invisible to the society. Some have been at sea for 40 years safeguarding the nation's oceanic territory, often spending 200 days on voyages and separated from their families for most of the year.

The commander on my ship gave up a merchant navy salary six times higher to join the CMS 20 years ago.

Some of the crew were still training and hoping to get navigation certificates.

Then there was the translator, in her 20s and the only woman on board, whose favorite pastime on board was singing. And the captain, a history buff. He told me he read all the history books in the college library when he was a student.

Just as we were disembarking at Guangzhou, I heard an announcement on board that all crew should return to duty two days later.

I hoped they could stay with their families for a few more days before they sailed out on another mission.