Peter Thompson, a well liked and well trained kayaker from Canmore is missing and presumed dead after disappearing over a waterfall on a the Cheakamus River in Whistler, B.C. (Photo courtesy Saskatoon Whitewater Kayak Club.)

CALGARY — Described as a well loved and experienced kayaker, a 19-year-old from Canmore, Alta., is missing and presumed dead after an accident on a Whistler, B.C., river.

Peter Thompson, as identified by friends and the kayaking community now mourning his loss, was paddling with others on the Cheakamus River in Whistler Friday when he went over a four-metre waterfall but did not resurface, said his good friend and kayaking pal Chris McTaggart, 26.

"It's a really straightforward waterfall and he had run it twice before the day before that," he said.

"It was just a complete freak accident -- he hit a rock and missed the stroke to get his bow in the air and he basically just submerged parallel to the waterfall and disappeared."

His paddle and lifejacket were found, but neither Thompson nor his boat reappeared.

"It's still really hard to even register what has happened because he's such a great person, such a well rounded young person, not materialistic at all, who had such a love for the outdoors," he said, adding his friend was always careful and would not enter certain rapids if he didn't feel comfortable.

Thompson was a coach for the Bow Valley Kayak Club and Alberta Whitewater Association.

"He just loved pushing the envelope, he loved the adventure," he said.

McTaggart said the search and rescue has been called off, and his family has arrived in Whistler.