The El Faro sank just before it was to be added to a Coast Guard list of vessels identified as having the most “potential for risk,” a designation that would have triggered more safety inspections.

The El Faro was to be included on the “targeting list,” which contained the top 10 percent of ships that the Coast Guard believed needed stricter scrutiny, Capt. Kyle McAvoy testified Monday at an investigative hearing in Jacksonville, Florida, before the U.S. Coast Guard Marine Board of Investigation.

The 40-year-old El Faro sank near the Bahamas in 15,000 feet of water after losing propulsion and getting caught in Hurricane Joaquin on Oct. 1. The tragedy claimed 33 merchant mariners, including four Mainers, just days before the Coast Guard planned to send the ship’s owner a message about the new designation.

When news of the ship’s disappearance came in, McAvoy said the connection was made immediately.

“The question became, internally, ‘What do we do now? We just lost the El Faro,”‘ McAvoy said. “We held the message.”

The Coast Guard did release the list with El Faro’s name on it after confirming that it sank. He did not say why, specifically, the ship was on the list but said age, expired documents or other problems are reasons for ships to make the list.

McAvoy’s revelation came during testimony on the sixth day of the Coast Guard’s hearing in Jacksonville looking into the El Faro’s sinking. Investigators are looking into whether misconduct played a role in the ship’s sinking, including whether mistakes were made in inspections. Coast Guard and National Transportation Safety Board investigators are participating in the hearing, and will release separate reports.

The four Mainers aboard the ship were Michael Davidson, 53, of Windham, the captain; Michael Holland, 25, of Wilton; and Danielle Randolph, 34, and Dylan Meklin, 23, both of Rockland.

They were graduates of Maine Maritime Academy in Castine, as was a fifth member of the crew, Mitchell Kuflik, 26, of Brooklyn, New York.

The ship’s second mate, Charles Baird of South Portland, wasn’t on board when the El Faro sank. Baird, who was on vacation during the ill-fated voyage, said during testimony that he gave in Jacksonville that he texted Davidson about the hurricane after seeing a weather report on the Weather Channel. He didn’t return a phone message seeking comment on Monday night.

In his final call for help, Capt. Davidson told company officials that he’d lost propulsion and his engineers couldn’t fix it. He said water was flowing into one of the ship’s holds, and the vessel had a “heavy list,” or tilt.

The Associated Press had reported that in the audio recording of Davidson’s call he said that water was flooding into his “three hold” or hold No. 3. There was some initial confusion over whether Davidson meant water was flooding into three holds, but the Coast Guard clarified the recording on Monday.

Previous testimony showed that the ship, owned and operated by Tote Inc., was due for its boilers to be serviced in November. Documents showed the boilers contained parts that inspectors said had “deteriorated severely” before the ship’s voyage from Jacksonville to Puerto Rico.

Still, Tote officials who reviewed those inspection reports described the scheduled maintenance as routine and said nothing identified in the boilers caused safety concerns, according to testimony. The company has said repeatedly that the ship was well maintained and fully inspected. The El Faro was last inspected by the Coast Guard in March 2015.

But in October, a few days after the El Faro sank, three former crew members raised questions about the ship’s structural integrity. CNN quoted the crew members as saying the El Faro had widespread rust and some leaks and may not have been equipped to handle a major storm.

Chris Cash, who said he last sailed on the El Faro in January 2015, told CNN: “(It) needed a death certificate. It was a rust bucket. You don’t take a ship like that … that ship wasn’t supposed to be on the water.”

Cash said he thought the company maintained the ship just enough to squeeze a few more trips out of it before having to replace it. The El Faro was scheduled for retirement from Caribbean duty, company officials have said.

The El Faro wasn’t a conventional container ship, but a “roll-on/roll-off” cargo vessel designed to carry trucks and other vehicles that are driven on and off the ship.

When El Faro departed Jacksonville, it was carrying 294 cars, trucks and trailers below deck, as well as 391 containers on its top deck.

Naval architects say the ship’s design and cargo configuration could have played a role in its sinking. During extreme weather, such as the 30- to 40-foot waves El Faro encountered in Hurricane Joaquin, seawater can pour through an improperly secured or damaged loading door, sloshing around the hangar-like decks and making the ship unstable. When water gets inside, it will slosh around the entire deck making the ship unstable.

Monday’s hearing also focused on data gaps in the safety inspection system for commercial shipping. Coast Guard Capt. John Mauger said that his office identified a “disturbing” increase in safety discrepancies found during vessel inspections between 2013 and 2014.

Mauger said that more than 90 percent of ship inspections are done by private classification societies, mainly the American Bureau of Shipping, and that there are reporting “gaps” in the information these groups share with the Coast Guard. The bureau of shipping did full hull and machinery inspections on the El Faro in February with no red flags, the company has said.

Because of the data gap, Mauger said, it is difficult to fill cracks in the system that may be allowing risky vessels to go to sea. He said they are working to fix communication between the Coast Guard, the American Bureau of Shipping and other classification societies.

“We don’t know what we don’t know. If they don’t notify us … we see that as a gap,” Mauger said.

The National Transportation Safety Board announced this month that it will launch a second mission to search for the El Faro’s missing voyage data recorder.

NTSB officials believe the VDR could contain clues about the challenges the crew faced as they tried to save the ship.

The 790-foot ship was found in about 15,000 feet of water near the Bahamas on Oct. 31, but its mast and base where the VDR was mounted could not be located. A date for the expedition has not been announced.

Staff Writer Dennis Hoey contributed to this report.