The man had intended to take the ferry across the largest river in northern Germany, but his satellite navigation system neglected to tell him that the ferry was still on the other side of the river.
Nonetheless the man drove straight over the end of the ferry terminal and into the water.
The man was driving with three passengers at Bleckede, southeast of Hamburg, on Thursday day morning when he plunged his car four metres down to the bottom of the river.
A spokesperson for the local fire service told The Local that it is pretty obvious where the terminal ends and the water begins and that there are several signs warning drivers.
But he explained that “it was still dark at the time and it was raining. Then there were four of them [in the car]. I personally drive most carefully when I'm alone.”
All the men were able to open their doors and swim to safety. But they were brought to hospital to be checked for hypothermia after their time in the river's cold currents.
The bizarre accident meant that the ferry was delayed for most of the morning as a team from the Water and Ships Office pulled the submerged vehicle from the water.