The second day of searches for missing Fort Lauderdale multimillionaire Guma Aguiar began Thursday with a sunrise flight over the Atlantic Ocean by aU.S. Coast Guard HC-144 plane.

The Coast Guard suspended its rescue mission around 9 p.m. Thursday.

While authorities investigate what happened to the 35-year-old investor who is believed to have gone boating Tuesday night, his mother filed documents Thursday in Broward County court seeking to become conservator or temporary guardian of his nearly $100 million fortune.

Aguiar’s 31-foot fishing boat, the T.T. Zion, washed onto Fort Lauderdale beach about 1:15 a.m. Wednesday, its lights on and twin outboard engines running.

Fort Lauderdale Police Detective Travis Mandell said Thursday investigators believe Aguiar got in the boat alone, “but that’s not to say he didn’t meet up with anyone.”

Ellen Aguiar’s petition says her son “disappeared as the result of mental derangement or other mental cause” or disappeared “under circumstances indicating that he may have died, either naturally, accidentally or at the hands of another.” It further states that he suffers from “severe bipolar disorder.”

The missing man’s cellphone and wallet were found on the boat by police, the 59-year-old Ellen Aguiar, of Pompano Beach, says in her filing.

He was last seen by the family nanny at home around 7 p.m. Tuesday, the petition states.

Aguiar kept his boat and his 77-foot yacht Zion berthed at his home in the 1500 block of Southeast 10th Street.

“Everyone is trying to figure out why he got in that boat,” Mandell said. The National Weather Service had issued a small-craft warning for winds of 15 to 20 knots, seas up to 5 feet and isolated thunderstorms.

The Brazilian-born Aguiar made his fortune in oil and gas. He attended Westminster Academy Christian school in Fort Lauderdale, and spent one year at Clemson University as a business management major on a tennis scholarship before he left in 1999.

He and his wife Jaime, 33, have three boys and one girl, ages 7 to 10 months.

Aguiar returned to his Jewish faith a decade ago, his rabbi said. He has made charitable gifts to religious and Israeli causes, and invested in professional soccer and basketball teams there.

READ MORE: WPTV