On Thursday around 4:30 p.m., Atikokan OPP officers responded to a call for assistance on Marmion Lake.
A 63-year-old Missouri man, who had entered the water to retrieve a boat, subsequently went underwater and did not surface.
On Friday around 12:15 p.m., members of the Rainy River District OPP, as well as a conservation officer from the Ministry of Natural Resources and Forestry, recovered the body.
The victim was identified as Nicolas Fox of Ballwin.
A post-mortem examination was to be conducted today in Thunder Bay.