What We Know About Whale Watching Boat That Sank, Killing 5

— -- The Canadian whale watching boat that sank Sunday, leaving five dead and one person missing, was moving in "fair" weather, according to Canadian authorities.

The boat sank off Vancouver Island near the tourist area of Tofino around 5 p.m. local time, authorities said. Carrying 27 people, the Leviathan II was a whale watching boat operated by Jamie's Whaling Station. The five victims were British nationals who were passengers and not crew members, ages 18 to 76, according to the British Columbia Coroners Service.

"Three were tourists vacationing from Britain, and two were currently residing in Canada while retaining their status as British nationals. The female deceased was residing in British Columbia while one of the males was residing in Ontario," the coroners service said in a statement. Further information about the victims will be made public once all family members are notified, the coroners service said.

The location where it sank was about 8 nautical miles northwest of Tofino, a spokeswoman for the Joint Rescue Coordination Centre told ABC News.

In addition to the center's aircraft and three Canadian Coast Guard vessels, many privately owned vessels responded to the distress signal, the center's acting sub-lieutenant Melissa Kia said. Those included boats from the Ahoushat First Nation. The search took place for roughly five and a half hours, during which 21 people of the 27 were rescued and five people were recovered "without vital signs," Kia said.

"When we launched air assets and sea assets at 5:30 p.m. local time Pacific, the weather was fair, with light winds and one meter seas," Kia said, referring to the wave height.

The Royal Canadian Mounted Police have taken on the search for the last person as a missing person's case, Kia said. Authorities have not yet released the identities of the victims or the missing person. The Royal Canadian Mounted Police did not immediately respond to a request for comment from ABC News.

Jamie Bray, owner of Jamie's Whaling Station, called it a "tragic day."

"Our entire team is heartbroken over this incident and our hearts go out to the families, friends and loved ones of everyone involved," Bray wrote in a statement on the company website. "We are doing everything we can to assist our passengers and staff through this difficult time. We are cooperating with investigators to determine exactly what happened. In the meantime, we want to extend our most sincere thank you to the first responders, rescue personnel, and everyone from Tofino and the local First Nations communities who assisted with the response efforts."

Bray wrote that he will provide further updates when information becomes available. Jamie's Whaling Station did not immediately respond to a request for further comment from ABC News.

The 65-foot long Leviathan II has three decks and can accommodate 46 passengers who can sit indoors or outdoors, according to the company website.