One person is presumed drowned and three went to hospital suffering from hypothermia after their boat capsized on Alouette Lake on Sunday afternoon.
The group had been up to the northern end of the lake, and were returning when they encountered mechanical difficulties, said Ridge Meadows Search and Rescue team manager Rick Laing.
They stopped at North Beach and made repairs to the boat, then continued on. But the boat started taking on water, then was swamped by a wave, and sunk. It was about 4 p.m.
The four occupants swam for shore, which was an estimated distance of 50 to 100 meters, but only three made it.
None of the occupants of the boat were wearing lifejackets.
Laing said a helicopter and two search and rescue boats combed the area where the boat sunk, while ground teams searched the shoreline. They searched from 5 p.m. until dark, but did not recover the fourth party member.
Laing said the occupants of the boat would have faced a challenging swim.
"Alouette Lake is very, very cold, and it was a windy day on the water," he said. "It [the cold[ really drains the strength out of you."
An air ambulance was called to transport the survivors to hospital.
Considering that three people were able to make the swim without life jackets, Laing said it is reasonable to infer that everyone could have made it to shore if they had been wearing them.
"Certainly they would have had better odds of surviving," said Laing.
"It should go without saying, but every year people drown, either here or in other parts of the province, because they're not wearing them."