Crews were called to a farm in Loxley, Warwickshire, at about 14:50 BST on Tuesday.
The man, in his eighties, had gone there to fish.
West Midlands Ambulance Service said: "He smoked his pipe and chatted to the farmer, who went into the lake in waders".
Firefighters carried the driver from his car back onto land.
"He wasn't hurt or even cold but crews removed his clothing to ensure he didn't get cold and he was driven home in the ambulance," a spokesman said.
An elderly man who accidentally drove into a lake sat in his car calmly smoking his pipe as he waited to be rescued, emergency services have said.