Officials said crew members could survive for 19 to 20 hours in the area of the Pacific being searched, and emphasized they are trained experts outfitted in superb protective gear.

The water temperatures in the area are in the mid- to upper 60s, and swells were two to three feet, but officials maintained Friday that they were mounting a rescue effort rather than searching for bodies.

"They are used to arduous conditions," Farris said in San Diego. "They are wearing excellent survival equipment. They are trained to use that equipment.

"They are also flying aircraft that are strong. You never know how an incident occurs. There have been many incidents where aircraft have cartwheeled or hit water and survived. Then other times they have landed softly and not survived."

But a Pentagon spokesman said in Washington Friday that hopes were dim.

"The search is still on, but it's likely taken the lives of nine individuals," Bryan Whitman said.

The huge C-130 aircraft is one of four such search and rescue craft based at McClellan Airport in Sacramento's North Highlands community.

The plane, painted bright orange and white, is a four-propeller craft with a wingspan of 133 feet and a length of 98 feet.

They "are painted to be seen, we want to be seen," Cmdr. Todd Lightle, assistant operations officer at McClellan, said Friday in an emotional press conference.

Federal officials were still trying to determine Friday what led to the midair collision.

Ian Gregor, a Federal Aviation Administration spokesman in Los Angeles, said civilian air traffic controllers were speaking to the C-130 pilot while the plane was flying in civilian airspace during its search for the boater.

"We terminated services when the plane entered a military warning area, which is controlled by air traffic controllers based at Naval Air Station North Island," Gregor said.

"We terminated service several minutes before the crash, and instructed him to call military air traffic controllers," Gregor added. "We don't know if he did."

Marine Corps and Coast Guard officials said they did not know how the collision occurred, although they noted that the San Diego airspace is crowded with military aircraft because of the number of military installations. Conditions were clear, although it was dark at the time of the crash.

Sacramento Coast Guard spokesman Lt. Randall Black said the C-130 Hercules aircraft conduct missions as far south as the equator, west to Hawaii and north to Alaska.

The orange-and-white planes, a ubiquitous sight over the Sacramento area as they take off and land after search and law enforcement missions, have a range of 4,000 miles and have a maximum speed of 380 mph.

Black said he could not recall any crashes of Sacramento-based Coast Guard aircraft in the past. The unit has been based at McClellan since September 1978, when it was moved from San Francisco because of concerns there was too much air traffic.

A C-130 Coast Guard crew from Hawaii arrived at McClellan at 10 a.m. Friday to relieve the station from other search-and-rescue duties while the rescue effort continues.

"What we're doing at the unit right now, because Coast Guard San Diego is in charge (of the search), our main priority is keeping in touch with the family members, keeping them up to date," Black said. "Obviously, our hearts and prayers go out to the family members."

The boater the C-130 crew was trying to save remained missing Friday.

David Jines had been on his girlfriend's sailboat Tuesday when he decided to return to his own sailboat moored on Catalina Island. He set off in a storm at 5 p.m. Tuesday in a 14-foot dinghy with a small Honda motor, Los Angeles County Sheriff's Sgt. Larry Knott said from Avalon.

The motor apparently was not powerful enough to bring him to land, and he disappeared; his girlfriend reported him missing Wednesday, Knott said.

"So far, we haven't been able to find him," Knott said.

Call The Bee's Sam Stanton, (916) 321-1091. The Bee's Kim Minugh and researcher Pete Basofin contributed to this report.