The search for a gigantic cargo ship that vanished four days ago during a hurricane in the Bahamas was to intensify at daybreak Monday as Coast Guard, Navy and Air Force crews keep looking for its 33 crew members, including four merchant mariners from Maine.

The Coast Guard said Monday morning that air crews were heading back to the scene to search for El Faro crew members. The Coast Guard has now searched more than 70,000 square nautical miles since last week. Officials are expected to update families of crew members and the media at a 10 a.m. press conference.

Late Sunday afternoon a Coast Guard search plane found a debris field that came from the 790-foot El Faro, whose captain is Michael Davidson, 53, of Windham.

On Sunday night, the Coast Guard said various objects were located in the vicinity of the container ship’s last known position, about 35 nautical miles northeast of Crooked Island, Bahamas.

The objects included life jackets, wood, life rings, Styrofoam, containers, cargo and an oil sheen – all within a search area of 225 nautical square miles. The El Faro, which left Jacksonville, Florida, on Tuesday bound for San Juan, Puerto Rico, was carrying 391 cargo containers as well as 294 trailers and cars. It was lost during Hurricane Joaquin.

Lt. Cmdr. Gabe Somma, a spokesman for the Coast Guard, said the discovery of the debris field demonstrates that the search for the missing ship is taking place in the correct area. “This validates our search pattern,” he said.

“We did not find the ship, which is not good news,” Somma said in a telephone interview late Sunday night. “But we remain hopeful that we can find the survivors in lifeboats or life rafts.”

Somma said the El Faro’s Emergency Position Indicating Radio Beacon, or EPIRB, emitted a signal around 7:30 a.m. Thursday, but there has been no contact with the ship or crew since then.

“We got one ping (from the EPIRB) and that was it,” Somma said. He said those transmitters can malfunction, but the fact that the device pinged only once is puzzling. The distress signal beacons interface with satellites and are used to locate missing vessels.

Somma said Sunday’s relatively good weather allowed for a more comprehensive search. Conditions during Sunday’s search included 1-foot seas and 15-knot winds with unrestricted visibility.

Those conditions contrasted sharply with the hazardous weather that searchers encountered Saturday.

Somma said the search was called off at nightfall Saturday because of the terrible conditions – aircraft flew close to the hurricane’s eye and encountered winds of 100 knots, with low visibility. Crews saw seas of 30 to 40 feet, he said, and that kept two Coast Guard cutters that were set to join the search in port Saturday.

One Coast Guard pilot said Saturday on Twitter that the conditions were the most challenging he and his crew had ever encountered

Two Coast Guard cutters – the 210-foot Northland, based in Portsmouth, Virginia, and the 210-foot Resolute, homeported in St. Petersburg, Florida – were assigned to remain at the scene northeast of Crooked Island on Sunday and were to continue to search throughout the night.

Somma said a news conference will be held at 10 a.m. Monday at the Coast Guard’s Air Station in Miami.

The cargo ship’s four crew members from Maine are all graduates of Maine Maritime Academy in Castine. They include Davidson, the captain, a former Casco Bay Lines employee who graduated from MMA in 1988.

Also on board the El Faro are crew members Michael Holland of Wilton, who graduated in 2012; Danielle Randolph, 34, of Rockland (2004); and Dylan Meklin, 23, a third assistant engineer from Rockland (2014).

Crew members’ families from Maine headed down to Florida, where they met with Coast Guard officials and got up-to-the-minute reports on the progress of the search effort.

Holland’s mother, Deb Roberts, created a Facebook page Sunday called “Making Waves for Mike – Bring the El Faro Crew Home Safely.” As of Sunday night, more than 1,000 people had joined.

Roberts reported on Facebook that the crew members’ families met with Coast Guard officials at 6 p.m.

“I caution each and every one of you not to take the news reports as gospel. Some media outlets are sensationalizing the snippets of information,” Roberts wrote.

“A container was found that was confirmed to belong to El Faro. To put that in perspective, though, winds were 140-plus miles per hour … not surprising that a container would come off,” Roberts said. “Ships will continue to search through the night. Planes will be back at it at dawn. Please don’t give up! Keep the prayers coming.”

Meklin’s parents, Karl and Elaine, traveled to Jacksonville on Saturday to be closer to where the search was based, joining other families.

Davidson’s family declined to talk to the news media Saturday. Theresa Davidson, the captain’s wife, spoke to a British newspaper, The Daily Mail, on Thursday, saying her husband had extensive training and is extremely capable.

“If anyone can handle a situation like that, it’s my husband, so we are hopeful that he’s just waiting it out and that they’ll be rescued today,” she said.

Davidson’s daughter, Arianna, is a member of the University of Southern Maine women’s soccer team. Her teammates posed for a photograph Saturday before their game with Plymouth State in New Hampshire. Numerous players wrote “El Faro” on their forearms to show their support for their teammate.

Randolph’s mother, Laurie Bobillot, also was quoted by The Daily Mail.

Randolph “is usually the only female aboard the ship, but even though she is a short little girl, she can handle her own well,” Bobillot said in a written statement. “When she’s home, she’s all girlie girl. She’s an avid Barbie doll collector and loves to dress up retro-style, shop and bake. Ever since an extremely young age, she wanted to work on the ocean.”

A reporter from WCSH-TV interviewed Bobillot in Jacksonville. Bobillot told the reporter she received an email from her daughter alerting her that the weather had taken a turn for the worse.

But she also told her mother not to worry because if anything were to happen to her at sea, “It’s OK, I died doing what I wanted to do.”

“I just want everybody to keep her and the whole crew of the El Faro in their prayer chain,” Bobillot told the Portland TV station. “It’s in God’s hands now. That hurricane whammed them really, really hard.”

Bobillot told The Associated Press that Davidson “is a top-notch captain. He’s well-educated. He would not have put the life of his crew in danger, and would not have out his own life in danger, had he known there was danger out there. He had the best intentions. He has a family too, and he wanted to go home to them, too. That storm just came up way too fast.”

The search has covered 31,000 square miles of sea near the Bahamas, an area about the size of West Virginia.

The Coast Guard resumed its search for the ship at first light Sunday off the Bahamas. Three Coast Guard search planes concentrated on finding life raft-sized or smaller objects while a Navy plane searched for the ship.

“This is a dire situation,” Somma said.

On Sunday morning, Coast Guard ships and aircraft, along with private ships, spotted more debris and an oil sheen that may be from the El Faro.

Tim Nolan, president of TOTE Marine Services Puerto Rico, which owns the El Faro, said Sunday afternoon that another company-owned ship, the El Yunque, and a contracted tugboat both found a shipping container that appeared to be from the El Faro and observed what appeared to be an oil sheen.

“Our thoughts and prayers remain with the 33 individuals aboard the ship and their families. They are our number one priority,” Nolan said in a statement.

Somma said Sunday that the Coast Guard planes returned to the area where an El Faro life ring was retrieved late Saturday afternoon to determine whether other life rings and a life jacket spotted nearby belonged to the missing ship. A salvage tug was positioned at the last known position of the El Faro.

Somma said the retrieval of the life ring validated the Coast Guard’s search process.

He said just how the El Faro got caught in the eye of a Category 4 hurricane is a question that the Coast Guard cannot answer. He said the Coast Guard issues frequent storm advisories and even flies over advisory areas issuing radio alerts to the ships below. But he said there is a limit to what the Coast Guard can do to warn mariners of weather conditions.

He said the search was initially hampered by the sheer power of the storm.

Somma said Hurricane Joaquin “is an unusual storm. It is the most powerful storm in history that far north. It was only one mile per hour away from being a Category 5 hurricane, which that far north is unprecedented.”

The captain of a ship has final say about whether to leave port. The Florida Times-Union in Jacksonville reported Saturday that TOTE Services officials said the captain had been closely following the storm before leaving.

“He made his voyage plan based on all the information he had available,” said Phil Greene, president of TOTE Services, an affiliate of TOTE Maritime Puerto Rico. After putting out to sea Tuesday, the ship ran into Hurricane Joaquin, which strengthened to a Category 4 storm during the week as it lingered over the Bahamas. The El Faro’s crew made a satellite distress call Thursday morning to report that the ship had taken on water and developed a 15-degree list, but that flooding of the vessel had been stopped. That was the last message from the ship.

The Coast Guard and TOTE Maritime Puerto Rico have not released any information on the crew.