Hobart man dies at wheel of tractor

A man found dead at the wheel of a partially submerged tractor in suburban Hobart probably died from natural causes, police say.

The man in his 60s was mowing grass near Cove Hill Road at Bridgewater about midday on Monday, a short time before the vehicle plunged into a nearby river.

"Initial investigations indicate that the fatality has occurred from a medical condition," Sergeant Luke Griffiths said.