PROVIDENCE, R.I. (WPRI) — A Vermont man returned to the stand Friday as a civil trial surrounding a boat insurance claim nears its completion.

Nathan Carman, 24, was listed as a witness for both sides. He’s being sued by his insurance company over an $85,000 claim he made on his boat, the Chicken Pox, which sank during a fishing trip in 2016.

Carman and his mother Linda were missing for about a week until he was found floating on a life raft by the U.S. Coast Guard. Linda Carman was never found and is presumed dead.

BoatUS argues Carman invalidated his insurance policy by making modifications to the vessel which eventually caused it to sink.

Carman answered questions from both sides regarding the policy. He said he thought if the boat sank, he would automatically be covered, and he detailed the days he spent on a life raft before he was found.

The judge asked Carman some questions regarding the day the boat sank, inquiring why he didn’t radio for help and whether he searched for his mother.

Carman testified that when he noticed there was a problem, he first focused on getting the safety gear ready. He said he didn’t tell his mother the boat was taking on water, believing she would panic if she knew.

“She was more of a problem than a solution,” he said.

Carman said he instead gave her a task to keep her busy since she wouldn’t have been able to help fix the problem.

He said once the boat started sinking he got in the life raft and called out for his mother. He recalled seeing oil slick and debris but said she was nowhere to be found.

Following Carman’s testimony, Mass. General Hospital Dr. Mitchel Harris and oceanographer Richard Limeburner took the stand. Both cast doubt on Carman’s story of survival.

“I don’t see how a drifting life raft can drift upstream or drift upwind,” Limeburner said. “In my opinion, the location of where Mr. Carman was found conflicts with my estimation of his drift path.”

Both sides were given 15 hours to lay out their case. They each had around two hours remaining going into Friday and they made sure to use every second of it. It’s unclear at this time when closing arguments will begin.

The judge barred any questions or testimony not involving the insurance policy, specifically regarding his mother’s apparent death and the unsolved murder of his millionaire grandfather John Chakalos.

Carman’s aunts—Linda’s sisters—believe he murdered both people in hopes of inheriting a portion of Chakalos’ $44 million estate. Carman was considered a suspect in his grandfather’s murder but he was never charged in that case nor his mother’s case.

A lawyer for the aunts was in court for the trial. He released a statement on their behalf Friday afternoon, saying they were disappointed that the judge chose to limit the scope of the trial to just the insurance claim.