The victim, 65, was found at around noon floating in the middle of the lake, more than 50 metres from the shore in Kim Long Commune, after an overnight search.
Authorities said the body was taken to a morgue for autopsy to determine the cause of death.
According to local media, he was the director of a company producing scaffolding and steel materials in Chau Duc Industrial Park
He had travelled to the lake with a friend on Friday morning for stand-up paddleboarding. The pair paddled from Kim Long Commune to the opposite shore, where they rested and took photographs before setting off back across the lake.
His friend later realised he had disappeared mid-journey and alerted authorities.
Da Den Lake, covering about 250 hectares, is a popular outdoor recreation spot known for camping, fishing and paddleboarding.
