"The search continues to locate people unaccounted for," said Lieutenant Commander Desmond James of the Coast Guard's rescue center in the provincial capital Victoria.
The center said there were survivors, but James was unable to confirm the number.
"There were four people recovered without vital signs," he said.
According to local media, 11 people received medical treatment or were hospitalised.
A rescue helicopter, maritime surveillance aircraft and three Coast Guard vessels continued the search effort into the evening.
The 20-meter (65-foot) three-deck cruise vessel is owned by Jamie's Whaling Station and Adventure Centres of Tofino.
An employee who answered the phone said the company was focused on the passengers and crew and would not release information at this stage.