(Adds comments from boat operator, Transportation Safety Board)
By Paul Brian
TOFINO, British Columbia, Oct 26 (Reuters) - Five Britons were killed when a Canadian whale-watching boat sank on Sunday, and authorities were still searching on Monday for a sixth person feared drowned in the frigid waters of the Pacific Ocean off the coast of British Columbia.
The boat, carrying 24 passengers and three crew, sank on Sunday afternoon, sparking a rescue effort by the Canadian military, Coast Guard, fishermen and mariners from a nearby Aboriginal community. Five people were confirmed dead and one was missing, while 21 were rescued.
The casualties included four men and a woman, and ranged in age from 18 to 76, the provincial coroner said. All five were passengers on the boat, not crew. The coroner did not release any information on the missing person.
"My thoughts are with the family and friends of all those affected by this terrible accident," UK Foreign Secretary Philip Hammond said in a statement.
The Leviathan II, a three-deck cruiser that can carry up to 46 people, was operated by Jamie's Whaling Station and Adventure Centres. Whale watching trips usually last two to three hours.
The boat had lifejackets for 50 adults and 20 children, although passengers and crew were not wearing them, said Jamie Bray, owner of the tour operator.
That was in line with guidelines from Transport Canada, he said, which advises passengers risked becoming trapped inside a closed vessel if they wore lifejackets.
The Leviathan "did this exact same trip for 20 years, twice a day," he said, adding its skipper had 20 years of experience.
In 1998, a boat operated by the same company sank near Tofino, killing the ship's captain and a German tourist. Bray said a rogue wave hit that vessel, a smaller, open Zodiac.
Survivors and bodies were brought ashore in Tofino, a remote town of about 2,000 people on the west coast of Vancouver Island popular with surfers, hikers and tourists from around the world looking to catch a glimpse of humpback and Pacific gray whales.
"There was absolute pandemonium," said witness Sheila Simpson, who watched paramedics work to save injured victims and later comforted survivors: "They were in absolute shock."
Most of those rescued were taken to a hospital. Several have since been released.
Canada's Transportation Safety Board said its investigation into the incident could take several months.
(With additing reporting by Nicole Mordant in Vancouver and Leah Schnurr in Ottawa; Writing by Andrea Hopkins; Editing by Alan Crosby, Jonathan Oatis and Lisa Shumaker)
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