Second Body Found in Search for Missing Family Off Florida Coast; One Identified as Daughter, 17

Rebecca's body was recovered Wednesday in the Gulf of Mexico.

A second body has been found by Coast Guard searchers trying to locate a family of four who went missing in treacherous waters off western Florida.

The remains were not immediately identified. A body discovered on Wednesday belongs to 17-year-old Rebecca Kimberly, relatives said. She had been wearing a life jacket. Still unaccounted for are her father, Ace Kimberly, and brothers Donny, 15, and Roger, 13.

Read: Father And 3 Children Disappear During Sailboat Trip Off East Coast Of Florida

They were last seen at about 9 a.m. Sunday when they set out on their 29-foot sailboat near Sarasota, the U.S. Coast Guard said.

At a press conference Thursday, officials said they had also found a spent flare and a bucket containing a cell phone, a wallet, a GPS navigator and birth certificates. Crews are also investigating a bright light that was seen about 2 a.m., possibly from a flare.

"This is still an active search, although it is a dire situation," said Capt. Gregory Case. He declined to comment on reports from NBC News and the "Today" show identifying the body found Wednesday.

 There is still no sign of the boat, authorities said. Debris including shoes and a basketball were found  Wednesday.

The Coast Guard, and other agencies, are continuing to search for the family members, he said. It is not yet a recovery mission. "At this point, we haven't crossed that bridge," Case said.

The family encountered trouble about halfway through their 75-mile trip to Fort Myers Beach, where they were planning to meet Ace Kimberly's brother, who was going to help repair the boat, officials said.

"The vessel was not in the best of shape and they were taking it down there so the brother could help them work on it," Case said Wednesday. He noted Kimberly and the three children had been living on the boat for about a year in Sarasota.

The father called his brother about 3 p.m. Sunday to say he were in six-foot seas and was "attempting to survive with his children offshore of Englewood and requested weather information," authorities said.

Read: Mom of Missing Florida Teens Wants Boat Examined For Evidence of Possible Crime

The teens had been estranged from their mother, Pauline Solsberry, since she divorced their father nine years ago, WTSP-TV reported. "Even though I don't like the man, I hoped he would be taking care of his children and keep them safe no matter what happened," she told the station.

Coast Guard aircrews found a debris field about 33 miles off Sanibel Island Wednesday. In it was a tarp, four water bottles tied together, a tennis shoe, a propane tank and a basketball, authorities said.

Six of the boat's seven life jackets were also found.

Watch: Kayaks Found While Searching For Father And Children Who Disappeared On Sailboat