A 58-year-old Seattle man with family in Oak Harbor has been tentatively identified as the person who jumped off the ferry M/V Cathlamet as the ship was approaching Whidbey Island on Dec. 11.

Authorities said this week that Phil Erb of Seattle is believed to be the man who went overboard from the Cathlamet while it was sailing between Mukilteo and Clinton earlier this month. Trooper Keith Leary of the Washington State Patrol, however, said authorities could not say with certainty that Erb was the missing traveler, as a body had not yet been recovered.

Erb was reported missing to the Seattle Police Department a few days after the man overboard incident. He is the son of Bob and Shirley Erb of Oak Harbor, and a frequent visitor to Whidbey.

The Erbs declined to talk to a reporter Monday.

Father Nigel Taber-Hamilton of St. Augustine’s in-the-Woods Episcopal Church, speaking on the family’s behalf, said they believe Phil Erb is the missing passenger from the Cathlamet.

Taber-Hamilton said the Erb family became concerned after they received a package from their son on Dec. 13 that contained the house key they had given him.

“That was kind of a big red flag,” Taber-Hamilton said. “’Why is my son sending back my house key? He needs it.’”

The couple became even more concerned after their son did not come by for his typical weekly visit.

“They tried to contact him and were unable to do so, and got worried,” Taber-Hamilton said.

The minister said the family had not heard that a passenger had gone missing from the ferry, but were soon contacted by the Coast Guard and a chaplain from the Oak Harbor Police Department after they filed a missing person report.

The couple was shown a photograph taken of the man who had gone missing from the ferry, and the couple identified the person as their son. The photo showed Erb wearing a sweater that his mother had given him.

Taber-Hamilton said the Erb family has been members of St. Augustine’s for more than a decade, and that Phil Erb had also attended services at the Freeland church. He was a former software worker, and one of four children in the family. His two brothers live in Texas, while his sister lives in North Carolina.

He was twice married and divorced, and did not have children.

Taber-Hamilton said that Erb had put his affairs in order. The package was mailed to his family on Saturday, Dec. 10, the day before he jumped from the ferry. He also left the laptop he usually carried with him everywhere at his apartment in Seattle’s International District.

“He clearly planned this for a long time,” Taber-Hamilton said.

The minister said the family has also heard an account from the woman who witnessed Erb jump off the stern of the ship during the 10 p.m. sailing.

“He simply walked to the back of the ferry and lifted up the rope, the way you see the ferry workers lift it, stepped over the webbing, and put down his bag,” Taber-Hamilton said.

The witness said he appeared to grab something out of his bag, then simply jumped off the ferry.

Ferry service between Whidbey and the mainland was immediately halted after a witness reported a man going overboard, and the Coast Guard led an unsuccessful search for the missing man that night and the days that followed.

Taber-Hamilton said a memorial service for Phil Erb will be held early next year.