A Calgary man is missing and presumed dead in the Narrows area of Shuswap Lake, Sicamous RCMP said Tuesday.
Search and rescue crews were not able to find Kevin Boutilier, 25, after an incident Saturday afternoon.
A group of people were on a houseboat when one person's hat blew off, witnesses told police.
Some of them dove in to try to retrieve it, but ran into trouble as inclement weather pushed the boat away. More people jumped off the boat to come to their aid.
"Of the group in the water, one individual was last seen in distress and seen going under the surface several times and did not resurface in spite of one of his friends being alongside him who was attempting to assist him," Sgt. Dave Dubnyk said.
Police are now looking at recovery efforts, but note that this area of the lake is very deep and the terrain at the bottom creates challenges for divers using sonar equipment.