This is an archived article and the information in the article may be outdated. Please look at the time stamp on the story to see when it was last updated.

A 75-foot diving vessel named Conception caught fire Monday while anchored off Santa Cruz Island, prompting an hourslong multi-agency effort to find more than two dozen missing passengers believed to have been on board, authorities said.

The Coast Guard says 25 people have been located and nine remain unaccounted for.

Lt. Cmdr. Matthew Kroll says Monday night authorities have recovered 20 bodies and discovered five more. Those five cannot be recovered due to unsafe conditions under the Conception.

Four bodies had been recovered Monday morning and 16 others were recovered later in the day.

Kroll says authorities will continue to search overnight for the nine remaining people.

The boat was scheduled to be on a Labor Day trip that started at the Santa Barbara Harbor on Friday night, then was expected to head to San Miguel, Santa Rosa, Santa Cruz, Anacapa and the Santa Barbara islands before returning to the harbor at about 5 p.m. Monday, according to vacation website, Worldwide Diving Adventures.

The boat, which is based in Santa Barbara Harbor, can carry up to 46 people and has a large upper deck area, a built-in barbecue grill, bunkbeds, bathrooms and showers, according to the website of Truth Aquatics, a well-known Santa Barbara scuba diving operation.

The Conception is equipped with a fixed carbon dioxide engine room fire suppression system and an emergency radio beacon. There are also rafts and jackets for 110 passengers, according to the website.

The Los Angeles/ Long Beach Coast Guard station overheard the “gargled” mayday call at about 3:15 a.m. Monday, according to the U.S. Coast Guard.

“We threw everything that we had available that can get on scene as soon as we could,” Coast Guard Petty Officer Mark Barney told KTLA.

Six crew members were on the boat, and five were awake on the bridge, jumped off and were able to evacuate onto a good samaritan’s boat before the vessel sank 20 yards off-shore in about 64 feet of water, U.S. Coast Guard Capt. Monica Rochester said.

The passengers are believed to have been asleep below deck, according to Rochester.

Crews from the Coast Guard, Santa Barbara Fire Department, Ventura County Fire Department and Vessel Assist responded the burning boat.

“Right now they’re conducting shoreline searches for any available survivors,” Rochester said at about 9:30 a.m.

The boat had no recent safety violations, the Associated Press reported, citing U.S. Coast Guard records from last February and August 2018.

An earlier inspection from 2016 found a fire safety violation that resulted in the owners replacing the heat detector in the galley and promptly addressing the issue, according to the AP.

The diving company operating the Conception provides vessels that take passengers on diving trips along the California coast and around the Channel Islands.

The Conception primarily sails to Anacapa, Santa Cruz, Santa Rosa and San Miguel islands. The boat also visits Catalina, Santa Barbara, San Clemente, San Nicolas, and Cortez Banks islands.

The company’s boats are custom-designed specifically for diving, according to the company’s website.

The Labor Day trip included gourmet meals, kayaking, and an on-board biologist who shows divers marine life under the microscope.

“Divers have the unique opportunity to explore the pinnacles of San Miguel Island. The beginning of September is the best time to be at San Mig, which see strong winds and swell during much of the year,” the advertisement for the trip read.

Trips on the boat usually cost about  $665.