Mercer Island PD hopes sonar will lead to missing boaters

Cell phones left behind on boat gave little help in narrowing the search area.

The search for two missing boaters continues, a week after Mercer Island Police found the empty boat floating near Mercer Island on Labor Day. And there’s little info on exactly where the pair was on the water before the boat drifted south of Mercer Island.

On Sept. 2, at about 10:30 p.m. someone called police to report music coming from a boat offshore in the 7700 block of West Mercer Way. The music began at about 9:30 p.m.

Officers who responded found the vessel still playing music. But there was no one aboard the red 20-foot “ski type boat.” Police later determined that James Le, a 30-year-old Seattle man and his friend Vanna Nguyen, a 33-year-old woman from Burien, were on the vessel and missing.

The Coast Guard has been aiding in the investigation and used a helicopter to search the lake and ground. The Seattle Police Harbor Patrol also has aided in the search. Other marine units searched the water and shoreline and found a trailer and truck associated with the boat at Gene Coulon Park in Renton.

Friends and family told police that Nguyen was not a strong swimmer, and when she did swim she used a type IV flotation device, similar to the cushions used on stadium seats. The only type IV flotation device onboard was still present when police arrived and they have yet to recover any kind of flotation device from the water, said Commander Jeff Magnan with Mercer Island PD.

Left behind on the undamaged boat were the pair’s cell phones. Police examined the two devices in an attempt to pin down a GPS location of where the phones were last used.

“We have put some hope into the cell phones … to give us some data,” Magnan said. “Unfortunately, even though we were able to get into both phones, neither of them were used past 8:30 at night.”

That’s when Nguyen posted a video on Instagram. Police had already been given the video, Magnan said. After that the data indicates that the boat was somewhere south of the Interstate 90 bridge on the westside of Mercer Island. Their search area falls within these boundaries and stretches to the southern tip.

“Kind of unreal how big of an area we have,” Magnan said. “This is such a huge area and depth.”

What they did discover is that both parties entered waters through the Ballard Locks and traveled into Lake Washington. They then traveled to Gene Coulon Park, parked the boat before going on a bike ride. At some point they decided to take the boat out on the water for a dinner cruise. That’s when the data ends.

“With the unfortunate response with cell phones, we are now concentrating on the areas that we know he has gone to in the past,” Magnan said. Those close to the missing man shared the spots Le would often frequent.

Police have created a picture of what lurks beneath waters using a side scan sonar. So far, they have been able to identify a couple of target areas that will be further examined.

And while others have planned search parties, Magnan said the searches could hinder investigations. Divers could stir up silt sitting at the bottom of the lake, and cover up areas of interest for police. Recreational divers also put themselves in danger when exploring the deep depths of the lake.

However, Mercer Island Police will continue their efforts to find the missing pair, even as the summer ends and weather patterns shift to fall.

“Just because it’s starting to rain, it doesn’t mean we’re not going to look aymore,” Magnan said. “We’re going to continue investigations and follow any credible lead we get. We are going to continue this until we’ve exhausted all efforts and at this point we haven’t.”