Updated

Two teams of rescuers prepared Monday to dive into typhoon-roiled waters off the Philippines to find a way inside a capsized ferry in a desperate effort to locate some 800 people believed to be aboard.

If Tuesday's planned underwater missions fail, a tugboat will be on standby with gear to cut through the ferry's hull as a last resort — a prospect complicated by a cargo of bunker oil that could leak and turn the human disaster into an environmental one.

Experts were studying the ferry's schematics in case they have to drill the access hole.

The divers, however, will get the first shot, coast guard chief Adm. Wilfredo Tamayo said, "looking for open hatches or doors on the side of the ship, diving underneath, breaking cabin glass windows if we can break them or cut an opening."

"We'll do this at the earliest opportunity, weather permitting," Tamayo said.

On Sunday, divers heard no response when they hammered on the hull, but officials refused to give up.

"We're not ruling out that somebody there is still alive," Tamayo said. "You can never tell."

Hundreds of people are feared to have been trapped when the ship suddenly tilted and went belly up Saturday at the height of the powerful storm that left 163 people dead in flooded communities in the central Philippines.

All that was visible Monday of the 23,824-ton, seven-story Princess of Stars was one end poking out of the waters off Sibuyan island, still churning after Typhoon Fengshen's full force swept through.

Only 38 ferry survivors have been found, including 28 who drifted at sea for more than 24 hours, first in a life raft, then in life jackets, before they were found Sunday about 80 miles to the north in eastern Quezon province.

A U.S. Navy ship carrying search and rescue helicopters was headed in, and a P-3 maritime surveillance plane also was being dispatched. "We want to express our condolences to the Philippine people," State Department spokesman Tom Casey said.

Officials initially reported 747 passengers and crew were aboard the ferry, but said Monday that it was carrying about 100 more. Capacity was listed as 1,992 people.

The coast guard said it was checking a survivor's report that at least one group of people — some dead, some alive — had been spotted bobbing in the sea.

Six bodies, including those of a man and woman who had bound themselves together, have washed ashore, along with children's slippers and life jackets.

While some relatives tearfully waited for news, others angrily questioned why the ship was allowed to leave Manila late Friday for a 20-hour trip to Cebu with a typhoon approaching. President Gloria Macapagal Arroyo said the ferry never should have departed.

Sulpicio Lines said it sailed with coast guard approval. The government ordered the company to suspend services pending an investigation and a check of its other ships' seaworthiness.

Debate also began anew on safe-sailing rules in a country prone to storms — Fengshen was the seventh typhoon this year — and dependent on ferries to get around the sprawling archipelago.

The company said it will give $4,500 in compensation to relatives of each person who died, along with financial assistance to the survivors.

The storm continued to dump rain on Luzon island and generate strong winds Monday as it headed toward China and Taiwan.

The Philippines was the scene of the world's worst peacetime maritime disaster when the ferry Dona Paz sank in 1987, killing more than 4,341 people.

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