Last year, a Laotian vessel sent out an SOS after it ran aground on a sandbank. Li and his crew attempted to pull it free by using a 1-meter-diameter metal pole driven deep into the earth of the riverbank as a winding post for a steel hawser, but the ship wasn't powerful enough to dislodge the stranded vessel, which was heavily overloaded. Sanlang Wangerjia, head of the Waters Division, ordered the cargo to be transferred to other ships and six hours later the vessel was floating freely again.

Merchant ships, which usually weigh less than 200 metric tons, find it easy to navigate the river, but the 450-ton patrol vessels are difficult to maneuver in shallow water. As a precaution, before the voyage began the captains drew up charts showing the precise locations of sandbanks and prominent underwater rocks.

Around six months ago, the captains came up with the idea of requesting a hydropower plant upstream in Jinghong, the capital of Xishuangbanna, to raise the water level and facilitate navigation, said Li. "It worked really well and the river became much safer," he said.

Cooperation extended

Currently, the joint headquarters at Jinghong is home to 12 police officers from Laos, Myanmar and Thailand. They coordinate the patrol boats' work and take charge of any emergencies in the area. Some of the non-Chinese officers are learning Mandarin so they can act as interpreters and further improve communications.

Police Colonel Charkerit Mongkouri, head of the 11th division of the Thai Marine Police, undertook his sixth tour of the Mekong with Chinese ships in November. He commands 153 men in the Thai provinces of Nangkai and Chiang Rai and is responsible for the security of the north and northeastern parts of Thailand.

More than 60 officers based at three stations patrol the stretch of the Golden Triangle where the river serves as the border for Myanmar, Laos and Thailand. Charkerit said the highly visible patrols had overawed those involved in the drugs trade on the river.

"When the patrol teams supervise security, it's definitely a good thing for people using the transnational river. The place is now much safer and we have seen an increase in the volume of goods entering and leaving Thailand in this area since the end of last year," said Charkerit.

Chinese and Laotian border police check a Laotian merchant ship.

More cover stories:

China laborers go abroad	Gift ban applies to festivals	Life after jail release	Logging out of an Internet addiction