Rescue efforts continue Sunday night to locate the remaining six passengers who were aboard a float plane that crashed off the coast of Saturna Island.

Authorities believe the plane went down at about 4:10 p.m., shortly after taking off from Lyall Harbour.

Eight people, including one infant, were onboard.

Lt. Paul Pendergast of the Joint Rescue Coordination Centre in Victoria says only the pilot and one female passenger have been located.

"They are en route to Victoria General Hospital by airlift," Pendergast said. "The pilot is in serious but stable condition, the passenger is in stable condition."

The ocean is 40 feet deep where the plane went down.

Pendergast says several Coast Guard vessels, am RCMP search boat, a fixed-wing aircraft and a helicopter are all assisting in the search.

Christy Clarke of Vancouver-based Seair Seaplanes confirmed the downed plane belonged to the company, and said the aircraft was making a scheduled stop at Saturna to pick up two people on the way to Vancouver.

She said the company is still trying to confirm exactly what happened.

"Right now we don't know what caused the incident," said Clarke. "We're just waiting it out right now."

Saturna Island is located at the eastern edge of the Gulf Islands, more than 50 kilometres south of Vancouver.

Tune in to CTV News at 11:30 p.m. for the latest on this breaking story...

With files from The Canadian Press