A Marysville man is believed to have taken his own life after authorities recovered a dinghy that was abandoned and adrift near Stuart Island Friday afternoon, and found a suicide note tucked inside.

In addition to the note, San Juan County Sheriff Bill Cumming said other items found in the dinghy include the 60-year-old man’s drivers license and Social Security card, as well as some identifying papers and various clothing items.

As of Monday, Cumming said the whereabouts of the man’s vehicle and boat trailer were unknown, but that he may have taken a ferry to Orcas Island and launched the 14-foot dinghy, which was equipped with a outboard motor, somewhere on the island. Deputies have been searching the island to locate the vehicle and trailer, he said.

“At this point, it’s an open investigation and we’re working with the Marysville police to contact the next of kin,” he said. “From what we’ve been able to piece together it appears he was depressed.”

The man was unmarried, Cumming added.

On Friday, the U.S. Coast Guard launched a search for a person possibly in the water after an unmanned dinghy was reported adrift in the vicinity of Boundary Pass at about 1 p.m. That search, which involved a Dolphin helicopter and a 87-foot patrol boat, was suspended about eight hours later after the dinghy had been recovered and Coast Guard officials determined there was no chance of survival based on water and weather conditions.

The 60-year-old remains missing.

Water temperatures in Puget Sound range from 44-55 degrees, and hypothermia can prove fatal in 60 minutes or less, according to the National Oceanic and Atmospheric Administration.