Police and emergency services remain at the Cataract Gorge Reserve in West Launceston searching for a swimmer.
The Westpac Rescue Helicopter and Police Drone have been deployed to the area to assist with the search.
The female swimmer, aged in her 20s, reportedly became separate from her swimming companions around 1.10pm, and she has not been seen since.
The woman was last seen swimming in the Basin.
People are asked to avoid the area while the search is underway.