RCMP divers are baffled by their inability to find the body of a 19-year-old man who drowned in the lagoon at the Harrison Hot Spring beach Sunday.

"The dive team is absolutely beside themselves," Neil Brewer, Kent Harrison Search and Rescue manager, said Wednesday. "They just can't explain it."

He said search officials have "very reliable" information on where the young man went down - about halfway across the 150-metre wide lagoon - but divers have been unable to locate the body, despite using a side-scanning sonar that can detect objects as small as a beer can.

An expert was called in to test the sonar's software Tuesday, but no malfunction was found.

There are no currents in the lagoon - which is basically a self-contained, man-made pond - that might carry away a body.

But Brewer said there are weeds, growing up to six feet from the bottom of the lagoon, which is about 20 feet deep in the middle.

"The divers are definitely fighting the weeds," he said, but he also noted that past drowning victims have been found within hours.

Brewer believes there have been three drownings in the lagoon in the 19 years he's been with the search and rescue unit.

"Considering the number of people who swim in the lagoon, a drowning every two to five years is a fairly rare occurrence," he said.

The 19-year-old swimmer in Sunday's incident, whose name has not been released by police, was swimming across the lagoon with a friend at about 2:30 p.m.

Agassiz RCMP Staff Sgt. Mike McCarthy said while the lagoon appears small, some swimmers under-estimate the distance and panic when they get into trouble.

Although the lagoon is promoted as a warm-water alternative to the cold waters of Harrison Lake, the village does not provide lifeguards or life-saving equipment.

"That may be something in the future our council takes a look at," Harrison Mayor Ken Becotte said Wednesday.

But the "bottom line is everybody who uses (the lagoon) does so at their own risk," he added, and there are several warning signs to that effect posted around the lagoon.

However, George Angus, a Chilliwack resident who has made the Harrison beach a vacation spot for over 30 years, said he believes the village has an obligation to ensure the safety of swimmers at the lagoon where "at least" three drownings have occurred.

"It's scandalous," he said. "It's got to be dealt with some time."

He also believes the village should re-open culverts in the lagoon that would create currents of cold water from the lake to deter the growth of weeds.

But former Harrison Hot Springs councillor John Green said the culverts "were doing nothing" to control the weeds, and were "lost" when the beach was "re-built" about nine years ago.

"They were buried," he said.

Mayor Becotte said the village is looking at some "more organic ways of getting the weeds under control," but they are "not usually an issue" because they are well below the surface.

Angus said the weeds make it difficult to find a swimmer who has gone down, but may still have a chance for resuscitation.