ABOARD THE USS SARATOGA, DEC. 23 -- The crew and commanders of this aircraft carrier gathered in a hangar bay overlooking a calm, gray ocean this afternoon to mourn the 21 men who died early Saturday when an Israeli shore ferry capsized.

"Tragedy struck us like an earthquake or a lightning bolt," said Rear Adm. Nick Gee, the commander of the 6th Fleet Task Force, as he stood before a table laid with 20 caps and flags in memorial to the dead. "Today is a day to shed a tear, to say a prayer."

Helicopters circled over Haifa Bay as the memorial service took place, searching for the last American missing in the accident.

The 20th body to be recovered by rescuers and divers from the water was brought to shore this morning.

Gee said the Navy has concluded that the last missing man also had drowned, bringing the final death toll to 21.

The Israeli navy was preparing today to raise the sunken ferry, the 57-foot Tuvia, in an effort to discover the cause of the accident. Witnesses and survivors said the double-decked craft suddenly tipped over in choppy seas as it stood near the Saratoga, sinking in about 15 seconds. It was carrying 102 crew members of the carrier returning from Christmas shore leave in Haifa.

In a press conference here, Gee said that while the U.S. Navy had not yet reached any conclusions about the cause of the accident, he regarded the event as an aberration that did not mandate any changes in the procedures for visits by U.S. ships to Haifa, a regular port of call.

"We are not going to change the location of the ship," which stands about one mile from shore, Gee said. "We are not going to change the procedure we have. We are anchoring in an environment you would find in 100 ports in the world."

Some Israeli commentators have expressed concern that the accident could hurt Operation Desert Shield in the Persian Gulf, of which the Saratoga is a part. They say the accident could call attention to military ties between the United States and Israel at a time when Washington is trying to hold together an alliance of Arab countries opposed to Iraq's occupation of Kuwait.

However, Gee and other Navy commanders strongly praised the Israeli military and authorities in Haifa for their help following the accident.

"I couldn't have a warmer and more thankful feeling than we have now for all those who helped us" in Israel, Gee said.

Israeli rescue ships and helicopters found many of the 81 sailors who were rescued from the water Saturday morning, and Israeli divers recovered most of the bodies of the dead from the sunken ferry.

Haifa hospitals treated several dozen injured, including two who remained hospitalized today.

Today's memorial service was attended by several dozen wives of Saratoga sailors who had flown to Israel from the carrier's base at Mayport, Fla., to be with their husbands at Christmas.

Sitting near them at the head of the assembly were a number of the survivors of the ferry disaster, some of whom wept openly as the dead were honored with a wreath tossed overboard and firing of volleys by a Marine guard.

"I'm just happy to be alive. I still can't believe that it happened," said John Deering, a 23-year-old seaman from Seabrook, N.H., who spent about 40 minutes in the water before being rescued.

As he struggled to stay afloat that dark night, Deering said, "I was just thinking of my wife, and how I wanted to see her again when I got home."

At the front of another rank of sailors, his right arm in a sling, stood 3rd Class Petty Officer Eleazar Gonzalez, 23, from Miami. Gonzalez, who was riding on a ferry that followed the Tuvia, pulled a number of his shipmates out of the sea while precariously hanging over the side of his own vessel, supported by sailors holding his ankles.

"There were people floating all over the water," Gonzalez said. "And it was pretty hard getting them up. There were pretty big swells."

In the course of rescuing about a dozen men, Gonzalez injured his own arm.

But he denied that he rated hero's status. "All in a day's work," he said.