"I was heading in for a perfect landing and then bang, the plane turned upside-down," financier and pilot Sven Hagströmer told the Expressen newspaper.
The 70-year-old Swede was out for a spin at the end of last week when the accident occurred, as he tried to land the sea plane on the waters of the Norrtälje municipality.
"I was hanging upside-down in my seatbelt and the water rushed in. Then I could only think: It's getting really, really cold here," he told the paper.
As soon as the water reached Hagströmer's head, he took a deep breath, unclipped his safety belt, and swam to the surface.
Ninety minutes later, the pilot was found clinging to the floating plane's pontoons by passing women in a motorboat.
The 70-year-old admitted that the crash was his own fault, as he forgot to take up the landing wheels when approaching the water.
Hagströmer told the paper that the incident would mark his last behind the controls of a plane.