RCMP began searching Blackstrap Lake on Monday after a man was reported missing in the area over the weekend.
People in the area say a man was jet skiing on the lake Saturday evening when strong wind gusts moved into the area Saturday around 8:45 p.m.
In a news release, RCMP said the 36-year-old man was the lone operator of the jet ski.
A search began immediately, with Dundurn Fire and Rescue, STARS air ambulance, Saskatoon police air support and Saskatoon Fire Department all assisting.
The Manitoba RCMP Underwater Recovery team arrived around 1:40 p.m. on Monday to begin the underwater portion of the search.
RCMP will remain at the north end of the lake where the man was last seen and the corresponding search began. As the search continues, officers are restricting boat traffic at the far end of Blackstrap Lake, north of the resort community of Shields.
Officers ask the public to use alternate boat launches during the search so sufficient space is provided to the RCMP.