After the U.S. Coast Guard intercepted the freighter Wing Fung Lung on the high seas last month, the smugglers who were bringing 249 illegal Chinese immigrants to America attempted to sink the ship. When that failed, they tried to blend in with the immigrants, start a riot, set fires, and overpower U.S. sailors.

On his first night aboard this floating nightmare, the commander of the Coast Guard boarding party, Lt. j.g. Robert Borowczak, lay awake worrying that his crew might not have captured all of the smugglers, known as "snakeheads," and wondering what mayhem might come next.

The rust bucket and its desperate human cargo were intercepted Dec. 9 about 300 miles off the coast of Guatemala, the most recent in a series of incidents that have caused the Coast Guard to declare that intercepting illegal migrants has become a more dangerous business than running down drug smugglers.

"As smuggling in human cargo becomes more lucrative, the propensity for violence has risen, and in addition to the smugglers using force, the migrants have become more willing to jeopardize life and limb," said Cmdr. Jim McPherson, a Coast Guard spokesman.

For six days and nights, the crew of the Coast Guard cutter Munro provided food, water and medical attention to the migrants who had spent two months jammed on the Wing Fung Lung in a doomed effort to enter the United States. But keeping order proved the greatest challenge. The boarding party had to resort numerous times to batons, pepper spray and handcuffs, according to Borowczak and other crew members who returned to their home base at Alameda, Calif., on Monday night and provided the first full accounts of the incident in telephone interviews this week.

Since a surge in the number of Chinese smuggling vessels crossing the Pacific began last spring, the Immigration and Naturalization Service has repatriated 872 migrants to China. Dozens more have been caught in U.S. ports, and unknown hundreds have made it to America, where many end up working in sweatshops or kitchens to pay off debts of $30,000 or more for the illicit passage. Along the way, the Coast Guard has recorded 18 incidents of violence--compared to only one in the whole of 1997--during missions to stop illegal immigration.

Chinese snakeheads, often associated with criminal gangs, are not the only culprits. Cuban migrants intent on making it to Florida have repeatedly threatened Coast Guard personnel with machetes in recent months.

"Over the years, I have handled thousands of migrants--Haitians, Cubans, Chinese and others--and in the past, they were always compliant and pretty much resigned to their fates. But now you see people who are absolutely determined to reach their destination, and they'll fight back when they realize you are going to stop them," said Capt. Wayne Justice, a 22-year veteran of the Coast Guard.

Justice was in command of the Munro, on a drug patrol in the eastern Pacific, when a Coast Guard plane spotted a suspicious freighter. The Munro came alongside the vessel that night and sent a boat to investigate.

The freighter's crew said they were carrying rice, then plywood. They said only six people were on board, but at least that many could be seen looking out portholes. The master of the Wing Fung Lung refused a request to inspect the ship. The Munro fell back to follow at a distance as the Coast Guard checked the ship's registry. After a day, Justice learned that the freighter was not a Taiwanese vessel as its crew had claimed.

At that point, it was legally a "stateless vessel" and the Coast Guard had authority to board it under international law.

At first light, the next morning the Munro launched its helicopter to take another look--and the chopper reported hundreds of people on the deck. By the time the cutter closed in on the freighter a few hours later, the Wing Fung Lung was wallowing in the sea, and there seemed to be panic onboard.

As he led a boarding party of 25 onto the freighter, Borowczak immediately ordered engineers to determine whether the ship was safe. They discovered a foot of water in the engine room and valves that had been opened to scuttle the ship. On the fantail, the only functioning life raft was partially inflated.

"After they saw our helicopter, the smugglers apparently concluded we were coming after them and decided to sink the ship right there, leaving more than 200 people to their fates while they escaped," said Justice. The Coast Guard crew made repairs and pumped out the freighter, which the Munro took under tow.

Meanwhile, chaos reigned on deck and in the main hold, where more than 200 male migrants had lived without sanitation facilities or bedding during the long passage from China. Following what has recently become standard practice in such situations, Borowczak and his mates started looking for the "enforcers," the smugglers who manage the migrants.

"You spot the ones that are bigger, better fed, better dressed," Borowczak said. "You find the ones with tattoos and the ones who are shouting orders." About a dozen such individuals were rounded up and separated from the rest.

With a Chinese-born Coast Guard cook providing translation, Borowczak learned that the migrants had not eaten in two days and had not had water for more than 24 hours. At sunset, a boat from the cutter brought over a meal, but before the boarding party could dispense it, some of the enforcers started yelling orders into the crowd.

People rushed toward the buckets of rice and jugs of water, and began fighting over the food. Almost simultaneously two fires broke out below decks.

"We realized we had to get the enforcers out of there or we were going to have a riot on our hands," Borowczak recalled.

Two enforcers jumped a member of the boarding party and had to be repelled with pepper spray. Other men refused to move, wrestled with Coast Guard personnel or threw human feces at the Americans, and were subdued with baton strikes to their legs.

When Borowczak and another Guard sailor cornered the man who appeared to be the top enforcer on the ship, he charged them, flailing a length of wire rope. A blast of pepper spray to the face did not slow him down. Soon all three were on the deck wrestling, and the smuggler grabbed for the Guard sailor's pistol. In the tussle, a shot went off but discharged harmlessly into a bulkhead. Two more members of the boarding party rushed to the scene and subdued the alleged smuggler with batons.

With all the suspected enforcers isolated, handcuffed and under guard, life aboard the boat calmed down for a couple of days. Then one afternoon, the migrants tore down tarps that had been set up on the deck to protect them from the blistering sun, and several of them put on all the clothes they had. It was an apparent effort to give themselves heat stroke. They had seen the Americans evacuate a migrant who had suffered a concussion and apparently hoped that getting sick was a ticket off the freighter.

After several fainted, Borowczak, 22, had a medic put an intravenous line into one of the stricken migrants in full view of the others. "They didn't seem too anxious to get stuck with a big needle and went back to behaving themselves," he recalled.

After six days, the freighter and the cutter arrived off the coast of Guatemala, and immigration inspectors came on board. Eventually 249 Chinese nationals were sent home, and four suspected smugglers were brought to the United States this month to face a variety of criminal charges.

CAPTION: Chinese migrants packed the deck of the Wing Fung Lung after a Coast Guard boarding party took control of the ship off the coast of Guatemala.