A missing boater from Mercer Island is presumed drowned in Lake Washington and the search for his body was suspended Sunday until sonar equipment becomes available, according to the King County Sheriff's Office.

"At this point, we presume he likely fell overboard and drowned," Sgt. Cindi West said of 67-year-old Richard Sweezey.

West said the sheriff's office doesn't own sonar equipment to search a large area of Lake Washington between Sweezey's boat slip at the Queen City Yacht Club in Portage Bay and the spot where his 48-foot boat, a 1965 Chris Craft Roamer, drifted onshore in Kirkland on Friday night. The Seattle Police Department and the Pierce County Sheriff's Office own sonar equipment, "but they're both unavailable now," she said.

Sweezey was last seen about 1 p.m. Friday by a friend at the yacht club, who loaned Sweezey a life jacket. Deputies later found the life jacket onboard. They also found a portable generator running and a tool in the water, but no sign of Sweezey.

According to West, Sweezey's boat had been completely stripped. "He was doing a total remodel, inside and out," West said, noting there wasn't a rail on the boat as there normally would be.

"If he fell overboard fully dressed, it would be hard to swim back to to the boat if it was drifting," said West. She said there is no indication Sweezey intentionally disappeared.

Investigators ask anyone who may have seen the boat on Lake Washington on Friday afternoon to call the King County Sheriff's Office at 206-296-3311.